Thun-Hohenstein Vault in Děčín-Chrást, Family tomb in Děčín-Chrást, Czech Republic

The Thun-Hohenstein Vault is the burial crypt beneath the neo-Gothic Chapel of St. John of Nepomuk in Chrást, part of Děčín-Podmokly. The chapel was built in 1869–1872 to plans by Vienna architect Friedrich Schmidt, with construction led by the young Josef Mocker. The crypt held 72 burial niches, 36 on each side, and two external tombs were added on the east side in 1889. The crypt entrance is now walled up.

The Děčín estate passed to the Thun-Hohensteins in 1628, when Kryštof Šimon of Thun bought it during the post-White Mountain confiscations. In 1822 František Antonín I took over the patronage of an 18th-century Baroque pilgrimage chapel and had a crypt with 72 niches built beneath it in 1834–1835, consecrated on 23 May 1835. The crypt undermined the chapel's stability, so it was demolished in 1868 and replaced by Friedrich Schmidt's neo-Gothic Chapel of St. John of Nepomuk, built 1869–1872 and consecrated on 21 January 1873.

The chapel is dedicated to St. John of Nepomuk and was consecrated on 21 January 1873 in the presence of the Bishop of Litoměřice; the founder František Antonín I was placed in the crypt the next day. Statues of saints once stood on the terrace wall east of the chapel and are now kept inside the building. The crypt itself has been walled up since 2022.

The above-ground chapel is open to the public, but the crypt itself has been walled up and cannot be entered. A two-armed staircase behind the chapel's axis descends to the crypt entrance, which was sealed as of 2022. The site is managed by the Zámek Děčín organization and is a listed heritage building.

The vault held 38 burials: 31 in the crypt beneath the chapel, two in the northern outer tomb and five in the southern one. The 1992 transfer concerned the 31 crypt burials; the seven in the outer tombs followed in 2007. A 2002 arson attack on the southern tomb led to its entrance being sealed with a concrete slab.