Acropolis, Kerameikos, and the Kerameikos Archaeological Museum. The city is also the setting for the Demokritos laboratory for Archaeometry, alongside regional and national archaeological authorities forming part of the Greek Department of Culture. Athens hosts 17 Foreign Archaeological Institutes which promote and facilitate research by scholars from their home countries. As a result, Athens has more than a dozen archaeological libraries and three specialized archaeological laboratories, and is the venue of several hundred specialized lectures, conferences and seminars, as well as dozens of archaeological exhibitions each year. At any given time, hundreds of international scholars and researchers in all disciplines of archaeology are to be found in the city. Architecture Athens incorporates architectural styles ranging from Greco-Roman and Neoclassical to Modern. They are often to be found in the same areas, as Athens is not marked by a uniformity of architectural style. A visitor will quickly notice the absence of tall buildings: Athens has very strict height restriction laws in order to ensure the Acropolis hill is visible throughout the city. Despite the variety in styles, there is evidence of continuity in elements of the architectural environment through the city's history. For the greatest part of the 19th century Neoclassicism dominated Athens, as well as some deviations from it such as Eclecticism, especially in the early 20th century. Thus, the Old Royal Palace was the first important public building to be built, between 1836 and 1843. Later in the mid and late 19th century, Theophil Freiherr von Hansen and Ernst Ziller took part in the construction of many neoclassical buildings such as the Athens Academy and the Zappeion Hall. Ziller also designed many private mansions in the centre of Athens which gradually became public, usually through donations, such as Schliemann's Iliou Melathron. Beginning in the 1920s, modern architecture including Bauhaus and Art Deco began to exert an influence on almost all Greek architects, and buildings both public and private were constructed in accordance with these styles. Localities with a great number of such buildings include Kolonaki, and some areas of the centre of the city; neighbourhoods developed in this period include Kypseli. In the 1950s and 1960s during the extension and development of Athens, other modern movements such as the International style played an important role. The centre of Athens was largely rebuilt, leading to the demolition of a number of neoclassical buildings. The architects of this era employed materials