There are three main types of structures associated with early Buddhist architecture: viharas, stupas, and temples. Viharas were originally simple shelters for monks to live and eat, but later became more permanent buildings for gathering. Stupas started as burial mounds for monks but evolved into towers, with their shape representing Buddhist philosophies. Temples feature a main pagoda building surrounded by other structures, with the pagoda having an odd number of levels symbolizing Buddhist beliefs.