Shimla is home to a number of buildings that are styled in the Tudorbethan and neo-Gothic architectures dating from the colonial era, as well as multiple temples and churches. The colonial architecture and churches, the temples, and the natural environment of the city attracts tourists. Attractions include the Viceregal Lodge, the Christ Church, the Jakhoo Temple, the Mall Road, the Ridge and Annadale which together form the city centre. The Kalka-Shimla Railway line built by the British, a UNESCO World Heritage Site, is also a major tourist attraction. Owing to its steep terrain, Shimla hosts the mountain biking race MTB Himalaya, which started in 2005 and is regarded as the biggest event of its kind in South Asia. Shimla also has the largest natural ice skating rink in South Asia. Apart from being a tourism centre, the city is also an educational hub with a number of colleges and research institutions.