Heritage Open Days are an annual celebration of England's architecture and culture that allows visitors free access to historical landmarks that are either not usually open to the public, or would normally charge an entrance fee to visitors, or that are always free to visitors and always open to the public. It also includes tours, events and activities related to architecture and culture. There are two types of events, drop in and pre book Heritage Open Days were established in 1994 as England's contribution to European Heritage Days, in which 49 countries now participate.