Geodetic marks on historic buildings

Caesarea geodetic mark

Geodetic mark located on the minaret of the mosque in Caesarea, Israel

Today, a few words about special metal details that we can find on historic buildings (and not only). Survey benchmark is a permanently stabilized point of geodetic network. They are used for geodetic measurements. In the past they used to be placed on old buildings, like churches - the best were already stabilized facilities that completed the settlement process. Many of these marks are so old that already can be recognized as monuments. Some of them can still be used as a part of contemporary geodetic network, some of them left only as historical curiosity. These details are often forgotten when renovating historic buildings. They are often thoughtlessly covered with paint but we should keep them and expose as integral part of the buildings' history.

Wroclaw cathedral

Location of historic geodetic mark on Wrocław cathedral

Geodesy marks

Geodetic marks - Płock cathedral and Wrocław cathedral

Sometimes we can also observe new local measurement points on historic buildings, which are used to check whether a given object is moving, e.g. as a result of construction works carried out nearby.


Contemporary geodetic mark on St. Adalbert's church in Wrocław

History written in wood

We often do not realize how much information is hidden in old beams of historic buildings. Going on a journey in the footsteps of former builders, we can learn interesting things about the structure and its former repairs.

Carpentry joint

Carpentry joint in Siedlęcin Medieval Tower (Poland)

In historic constructions, joints of wooden elements were made without the use of metal connectors. The elements were connected using carpentry joints, reinforced with wooden pegs (depending on the type of connection). Only at a later time, together with the increase in the span of the structure, began to introduce metal connectors. In uncomplicated constructions as well as during renovations and reconstructions, carpentry joints are used even today.

Crowned wall

Crowned construction with a saddle notch corner

Traces of ancient carpenters can become a guide for the history of the building for us, and old beams a source of knowledge about crafts and construction techniques. On the surface ot the wooden elements we can find carpenters' marks that simplified the assembly of the structure (they determined where in the structure the given element should be). They were usually made with chalk or pencil or cut with a sharp tool. The numbering was often Roman numerals or some variation thereof. Based on this marks, it is possible to deduce in which order individual parts of the structure were erected, as well as to determine which elements are original and which were inserted during subsequent repairs and renovations. Traces left on the surfaces of the processed elements of wooden structures can give us information about the tools used - traseology deals with the study of these traces.

Carpenter's mark

Carpenter's mark on the roof structure from XVIII century

Carpenter's mark

Carpenter's marks on the half-timbered structure form XIX century

It is worth to remember about carpenters' marks and take care of them during renovation! If their removal is necessary, due to biological corrosion, it is best to document them in advance.

Szombierki Power Plant in Bytom (Silesian Province)


Szombierki Power Plant in 2014

Szombierki Power Plant in Bytom (Ger. Kraftwerk Oberschlesien) - this amazing industrial building because of its monumentality, dark charm and not typical beauty is very often called an industrial cathedral.

Szombierki Power Plant

100 years has passed since the one of the biggest power plants in this part of Europe was built. What a century it was! This amazing modernist structure was opened in 1920 and designed by famous German architects Georg and Emil Zillmann.  In the 1940s power plant was able to generate 100 MW. With some necessary equipment improvements, it was working until 2011. Due to changes in the technology, the structure stop being used in designed way and the dark times has begun... They were some attempts to revive the object but not very successful. In 2020 Szombierki Power Plant was placed on the list of Europe's 7 Most Endangered Heritage Sites (

Szombierki Power Plant

What to do with such a huge structure? It is definitely worth protection but it is extremely difficult to find a new function. Maintenance of such a big industrial building costs enormous amount of money. It was planned to create here an educational, cultural, museum and entertainment center but for a few years we cannot see any progress there...

We hope this industrial treasure will have a bright future.

Szombierki Power Plant

Dušan Jurkovič – the Poet of Wood

Jiraskova Chata

Jiráskova Chata in Dobrošov

Dušan Jurkovič  was a famous Slovak architect and ethnographer from the turn of the 19th and 20th century. He was a creator of unique architecture style that was strongly influenced by folk motives. Many of his works involved wood creations - he is referred to be "the poet of the wood". He was creating objects with great attention to detail and perfectly matching the landscape, like mountain hostels, private villas, war graves units and many others.

This versatile artist has created timeless architectural works that became famous landmarks. You can find this masterpieces in the territory of Czech Republic, Slovakia and also Poland.

Our first meeting with Dušan Jurkovič architecture was in the Hradec Králové Region, in the area located very close to the Polish border. In this mountainous neighborhood you can find some of his fairy tale buildings.

Definitely, worth visiting is a place called Peklo, located in a deep valley ("peklo" translates as "hell"). There is a former mill that Jurkovič rebuilt into a restaurant for tourists in 1908-1910. A few kilometers from that place, in Dobrošov village, you can find a lovely mountain hostel Jiráskova Chata built in the years 1921-1924. It is a well known spatial dominant of the area. From the top of the tower you can admire the surroundings.

To be continued.

And remember... Dušan Jurkovič is definitely worth a trip to Hell!


Restaurant for tourists in Peklo