St Michan's Church is a church in Dublin, Ireland that was originally founded in 1095. The church was established to serve a colony of Danish Vikings who had been forced outside of the city walls after the majority of the Vikings had been killed or kicked out. The church was rebuilt in the late 1600s, and a large pipe organ was installed in 1724. It is believed that George F. Handel used this organ when composing The Messiah.
The big draw for St Michan's Church is in the basement. Below the church is a crypt with coffins, many of which are open. The bodies laid to rest here have mummified over the centuries with various theories as to why the bodies here have remained in a semi-preserved state. Some credit the limestone that makes the basement so dry, and others point to the methane gas from the former swamp land the church was built on. While the bodies have been preserved, the coffins have been disintegrating, often causing them to fall apart and reveal the mummies.