 Now, thank you for being here. Thank you, Martin. Thank you, Thomas, for the invitation to the session. And my presentation entitled Hidden Stairways at the Food of the Himalaya will present results from geophysical surveys and excavations carried out last year in the Popchika Valley in Bhutan. The main aim of this Swiss-Butanese project, or Bhutanese Swiss project, is capacity building in this small kingdom and the institutionalization of archeology in Bhutan. It's done by education of several people and involvement in the archeological research and also in practical training. So the project was initiated by Kama Vizir from Bhutan and it's in cooperation with ETA Zürich and a team guided by Philippe de la Casa and financed by the Swiss Lichtenstein Foundation for Archeological Research abroad. Small introduction into the location or the Kingdom of Bhutan is located in between China and in the north and India in the south. It's a similar size like Switzerland about 80,000 square kilometers but much less dense populated with less than one million people. And so it was my first time in Bhutan last year and when I came by plane to the capital, Timbu, I saw this mountain ridge from the plane and it's here in the northern part of Bhutan and it's called Ganga Pinsum and it's about more than 7,500 meters high and interestingly, it's the highest unclimbed mountains in the world and the reason for that is because mountaineering, it's not allowed in Bhutan. There are several hiking tracks but there's no alpinism as we know from other areas. And the reason for that of course is because the mountains are sacred and holy places. So the research was done in the Popchika Valley, it's located here in between central and western Bhutan in about 3,000 meters high. Here's a picture from the Popchika Valley itself. It's named after a famous monastery located within this valley and you see here in this area, it's a wet marshland and to refer to your presentation with a mountain so if you are standing here, you are looking a lot of mountains but not that high elevated or not that impressive from Tibet, I guess. Okay, first step was in archeological perspective done by the Bhutanese Swiss team over several years. It ends up in this map of historical sites. It's a Popchika Valley, it's about 15 kilometers long running north-south, here in the north there's a pass. This point here, it's a famous monastery I mentioned, it's located on a hilltop. You have several tributaries running from the east into this valley and here this pointed are several archeological finds. In total, there were 93 find spot mapped and among them there were 49 so-called burial mounds or artificial mounds which could refer to burials. Among other elements like terraces, artificial hills and so on. Most prominent, for example, is this one M1 near to the famous Gangtian Monastery and M49 near to the junction of this small stream into the main valley. Okay, so regarding the burial mounds, there's not that much known yet about the mounds in Bhutan. So referring to far as the north to Tibet, so I found this sketches about the shape and the dimension about burial mounds in Tibet. It was a scientific work from a team of Austria. You see there could be rounds, there could be rectangular in shape. But what is clear for the mountain or for the burial mounds in Bhutan, that they are endangered. For example, the Mount M49, it looks like this now. So it's a cutted mound as seen in the aerial pictures from 2011 and five years before, it was still existing at one of the bigger mounds in this valley. So there's a clear demand for research as well and for protecting the cultural heritage. Okay, the research approach last year was first, goes there and started geophysical perspective to get information about, or more information about this mound on an undistructed way. Six mounds were chosen for this geophysical surveys. Here's a map. There's a Mount M1 near to the monastery. One, another Mount M3, or here M1 is this picture. It's a isolated single one, but near to stone structures nearby and near to the monastery. Then another mount on the western edge of the valley. And a group of mounds located here in the southeastern area. For example, the big Mount M49 I already mentioned. Another Mount M31, which is much smaller, but also with a capped surface. You will see here next to this mound, a small pit discovered on site. And so also this mount could be located in a row. This, for example, is a group of three mounds or with prayer flags, one next to each other. We selected the center one for geophysical surveys. And the sixth one is also one of a bigger group located in a fenced area near to a nunnery cluster. So I will come back to results or select this three mounds to show you the main results of the geophysics. Okay, how to survey a mound geophysically. There are a lot of methods available. If you look for near surface features, mainly magnetometry issues. If you go into greater depths, examples from Greek, using seismics or gravity. If you have cavities like a new range, we choose two complementary methods, GPR and resistivity to mammography. GPR maybe you know from the recent excavations done in Norway. So there's a nice ship is in a burial. That's, yeah, the pictures are derived from GPR surveys. So very brief introduction into this methodology. So we used to, of course we have to think, okay, we go to Bhutan for one week. What can we carry? We use the single antenna. There's a survey wheels or a system with a certain frequency more focused on depths instead of high resolution. We'll always think about this beforehand. And yeah, the survey itself runs on parallel profiles. Here's one section of a profile. You get reflections here for example on the bedrock. If you put it onto the topography you have to measure and have several assumption about the velocity of the electromagnetic waves you get for example this cross section with a bedrock and here you see it clearly seen that this artificial mound is erected on a more or less solid bedrock and within you get reflections, diffractions from different features, mainly stone features. Okay, so complementary method. We applied ERT as much more effort because you have to put electrodes into the ground to get a current flow in the subsurface and so you measure the potential difference and then you can derive the resistivity distribution. It's always three dimensional. That's what that pictures should point out. Here that's a model you can derive if you make several measurements on parallel profiles and the main difference to GPR is that you can get a greater depth of penetration here visible. That's a three up to four meters achieved on Mount 31 for example. Okay, so that's where the two methods we applied in different ways. We had only six days for six months. I will show you results from three of these months. First, it's a single located Mount M1. The lower left picture showed the results of the topography measurements we did. Here you see these lines. Here that's the highest point, that's the valley. And as you can see, that's it's more or less some rectangular shape can be expected. With the GPS, we additionally measure the stones visible at the surface. Here it's more or less a scattered distribution in this picture, but in details. For example, the stones here are clearly visible as corner stones of a foundation. Here's a GPR, in this case we carried out in two directions. So the orange dots are the interpretation for a certain time depth. So that's this below the surface and one meter. You see it's more or less scattered, so less clear image in this case. We carried out some resistivity survey here. I have one section running diagonal around this mount. So that's the resistivity distribution. So there are high resistivity here, probably because of topography effects, but I won't refer to a sequence of low and medium resistivity visible in the sections. So mount 31, the center one in a row of three. We have clear indications of rectangular features. That's for depths of one meter. And if we sum up for several depths, we see that it's continuous in several depths. This rectangular linear features up to 1.6 meters. So also here we have a rectangular structure. And then came to mount 31. Here also we have clear linear structures below the surface in the depths about one meter, showing an X-shaped feature of about five by six meters. The pit nearby was not excavated, but cleaned during the first campaign in spring 2018 and derived in also some charcoal to get in date, which is a pre-Buddhist times. Okay, and then half a year later, the team from Christian Bader and colleagues started an excavation, so Salamount 31 was chosen for this, so it was already endangered. And so they excavated this. The results will be published soon. Here's some first impressions. So they reveal the X-shaped feature. Interestingly, it was open, so set of rectangular stones. And if we compare it to the geophysical surveys, we can say, okay, we clearly derive the main features, but also on the edge of this mount, there were some hidden steps. We did not see clearly in the GPR results. The reason for that is that we did only survey in one direction on this mount. And this could be to think for future service, you should be invest more time and work in two directions to gain all the information for the subsurface structures. Okay, so to sum up, we did a geophysical survey on six of, in total, more than 49 mounts, which give a good idea about the subsurface structures. We used two complementary geophysical survey methods. And four of these mounts, year 131, 133, and 136, they clearly point to rectangular structures. And the excavation at Mount 31 confirms these results. And to sum up, they are showing rectangular structure, probably platforms erected on a natural ground. And we conclude from the geophysical results and the excavation, that there are very likely no burials below this structure. And also on the big cap mount, 49, we see a leak that is erected on a bedrock. Main features are destroyed and there's no bigger structure below. Yeah, that's a final result. The intention was to show the different perspective if you use natural science to get answers for your archaeological questions, I hope. Thank you.