 It's a structure which was erected at the beginning of the 19th century. It has a very important historical value for us. So it's the reason why the monitoring was applied in this structure. The important dates regarding the structure as follows. It was erected at the beginning of the 19th century, around the middle of the 19th century. The fortifications were built around the structure. And then it was entered in the registry of monuments at the beginning of the Second World War. At the top you see the status of the structure around 1850. At the bottom is the current state of the structure. The following parameters characterize the geometry of the structure. It's 80 meters of base diameter. The diameter of the viewing platform at the top is 8 meters. It's 34 meters high, and there's very steep slopes of 40 to 60 degrees. And that's one of the reasons why we have a problem with this structure. Because when we had a very wet summer, let's say, in 1997, the structure failed in a very dangerous manner. So it almost had to be rebuilt from about the third from the top. Why so? Because in parts, at least because of geology, are the properties of the soils which were used to create the mound. It's made of very mixed types of soil. On top of limestone there is a subsoil layer and then silts and clays, which are very sensitive to water content. And then non-cohesive soil at the top of the structure. So when it was undergoing the rebuilding, let's say so, after the failure it was decided to have a very developed structural health monitoring system to put into place because of the continuous degradation of the structure, the cold conditions regarding the material and the slopes, not fully effective repairs, lack of documentation until 2012, and only surface observations existing until 2012. So until 2012, the following observations were made, only displacements were measured at certain points. With the registered displacements shown here in color, the biggest displacements were in range of half a meter, the smallest less than 50 millimeters. And this is the history of displacement at denoted points in the time period of 2002-2014 with additional detailed measurements at four indicated points on the surface of the structure. The structural monitoring system had been installed after the failure with a number of sensors connected to the data logging system and used to continuously measure the selected values, which are important from the structural point of view. Humidity and temperature in several points are measured to water pressure and water temperature inside the structure. Vertical displacements as well as horizontal displacements are measured in those points located, as you can see in this top view of the structure, with vertical displacements measured on several levels at the same point, in certain depths of the structure. Here are the locations, horizontal displacements and temperature and humidity measured at the indicated points. Here we see some pictures from the installation of the devices used to monitor the structure. Water pressure in ground pores were measured as well in order to be able to more... know the soil conditions in more detailed manner as the soil, the water pressure inside the ground pores is very important from the geotechnical modeling point of view for our considered object. Additionally, meteorological monitoring was played in the form of rain gauge, nanometer and pyranometer, which measures the sunlight intensity on the structure. This is to measure accurately the water content in the soil and to help predict the water level in the soil in order to know better what the situation may be with respect to our structure. Here you can see the results of the measurements at those indicated points, which are the changes in layer thickness for a time span between 2013 and 2015. Some part of measurement is missing at the indicated line. There are changes in base height at the same points, changes in soil layer thicknesses at the same points again, with initial configuration and decrease and increase of layer thicknesses because decrease as well as increase in layer thicknesses occurred in our structure during the monitoring period indicated here, which is a little bit more than a year here. Water pressure in time plus the temperature measurements, which you can see here are quite, regarding the water pressure are quite stable. Temperature of course changes due to the seasonal change in sun action and sun irradiation, horizontal displacement at the indicated points and precipitation in terms of rain, snow and fog. Of course the rain is the most important factor because the last several winters in Kraków were characterized with very little snow or low snowfall, but the rains from time to time are quite intensive. Wind direction, which may be not so very important for our structure, but it's also measured and monitored and recorded sun irradiation, which changes of course due to seasonal changes in the sun activity. So that's the available data, the data is gathered by an automatic system and it's available online, so there is no problem with access to the data. And the first conclusion that may be drawn from this data gathering is that the rainfall is the greatest danger for our structure, especially long duration and low intensity or very high intensity rainfall in short duration. And also the observations made so far indicate that the deformation begins at the ceiling of the limestone, so at the basis of the mount and is very irregular due to the nature of the soil used to create the mount. Additionally, this effect is made more dangerous because of this irregular soil distribution mountains to tilt mostly in the easterly direction. As this is a national monument, of course there is not a question whether to do something, but when to do something and when act to minimize the cost. So for the structural health monitoring the first question will be we expect at least two things. The first one is better information to model the soil action during the forecast life of the structure or the ability to monitor or to calculate, using computer simulations to calculate better the results that's the first thing. And then the second thing is quite obvious also, when to act to minimize the cost of the action because the monitoring system I don't think will be an additionally developed during the incoming time. It's as is, but we should do things we want to do and we should use the data available to make the most out of this data and this would be just to keep the structure, get the structure kept in the well shape preserved at the lowest cost possible. Thank you. In the context of value of information, right, you say it's a national monument, so it has largely a symbolic value. Yeah, that's true. How would you quantify this? It's a kind of confilight value, right? I wouldn't dare to quantify that and that's why I say that's not a question to do something or not to do something but when to do something to minimize the cost because of the historical value, of course, sooner or later something will be done to keep the structure in a good shape well preserved for the next generations. It was an interesting concept in a probabilistic context, right? Exactly. How to say if a value of this can be modified? It's a similar thing to find a value of, let's say, Mona Lisa painting. It's one, only, and unique. But still there may be a question. As long as you accept the final probability of failure you implicitly address the value. Agreed? But it's a different discussion. We have much more problems to solve today so therefore I would like to thank you again for your time.