There are three government columbaria and 57 private ones. The government-operated columbaria are at Mandai, Yishun and Choa Chu Kang. (A fourth government columbarium at Mount Vernon is due to close at an unspecified date due to redevelopment of its surrounding area into a public housing estate.) Private columbaria are operated by the Kong Meng San Phor Kark See Monastery, the Roman Catholic Church of Saint Mary of the Angels in Bukit Batok, and the Singapore Soka Association, among others. As with crematoria, there is a significant price difference between niches in private and government columbaria. A standard niche in any government columbarium costs less than $900, but one at the Kong Meng San monastery costs more than $15,000. The government columbaria allocate niches sequentially, and charge an extra $250 for any location change request; for an extra price, the private columbaria allow families to choose niche locations subject to availability, and even to pre-book niches before death.