The Mohammed ibn Zeid Mausoleum is an outstanding monument of Sultan-Kala. It is relatively small, but it arouses admiration with its original architectural solution. The interior of the mausoleum has a unique wall inscription in Arabic. The letters, intricately carved from fired bricks, stand out boldly against the background of the vegetative plaster pattern. It is said that the mausoleum was built over the tomb of Mohammed ibn Zeid, the representative of the Shia branch of Islam, the fifth-generation descendant of Caliph Ali in 1112-1113.