Vojenský lázeňský ústav, Military spa institution in Karlovy Vary, Czech Republic.

The Vojenský lázeňský ústav is a medical facility in the thermal spa region that draws on mineral-rich spring waters for therapeutic treatment. The building houses specialized rehabilitation services that make use of these natural thermal resources.

The project was drawn up in 1850 by Václav Hagenauer, architect to Count Buquoy. Construction of the Militärbadehaus began on 18 August 1852 and was completed on 30 June 1855; the building and its chapel were consecrated on 12 July 1855. It was the first comprehensive spa facility in Karlovy Vary and one of the largest military spa institutes in Europe. Free accommodation and medical care were offered, at first only from 15 April to 15 October, and year-round from 1901.

The building's nickname Kommissbrot (army bread) came from locals who found its plain facade too simple. In the dining room hangs Vilém Kandler's 1848 painting of Charles IV discovering the hot springs, made for the 500th anniversary of Charles University but never delivered to Prague. The chapel altar, carved in white Carrara marble by Julius Malzer and finished by Václav Levý in 1856, was covered by a curtain under the communist regime.

The building stands on the left bank of the Teplá, about 600 m north of the Vřídlo spring; the Sadový pramen spring rises in its basement, and one of its outlets is reached from the Sadová Colonnade in Dvořákovy sady. It is not military-only: the three-star hotel Sadový pramen, part of the military spa and recreation facilities, is open to the general public.

In the third floor is the oldest clock mechanism in Karlovy Vary, installed in 1855 and still running in its authentic form. The chapel in the south wing holds a white Carrara marble crucifix with two kneeling angels, completed in 1856 by Václav Levý after Julius Malzer began it.