Riga's chief draw is its Art Nouveau architecture — the city has the largest concentration of Jugendstil buildings of any in the world, mostly built in a frenzy between 1900 and 1914, with the densest cluster on Alberta iela and Elizabetes iela. The Old Town (Vecrīga) is compact, UNESCO-listed, and walkable in an afternoon; the Dome Cathedral, St Peter's, and the reconstructed House of the Blackheads are the set pieces. The Central Market in five huge repurposed Zeppelin hangars is one of the better markets in northern Europe. Out on the northern edge of the city, the Latvian Open Air Ethnographic Museum is one of the finest of its kind in Europe — over 100 historic rural buildings assembled in a pine forest on the shore of Lake Jugla.