Surviving colonial structures have been restored as close as possible to their 18th-century appearance, with traces of later buildings and improvements removed. Many of the missing colonial structures were reconstructed on their original sites beginning in the 1930s. Animals, gardens, and dependencies (such as kitchens, smokehouses, and privies) add to the environment. Some buildings and most gardens are open to tourists, the exceptions being buildings serving as residences for Colonial Williamsburg employees, large donors, the occasional city official, and sometimes College of William & Mary associates.