Prvního pluku 4, Protected tenement building in Karlín, Czech Republic.

The house at Prvního pluku 4 is a three-storey late Neoclassical corner building erected in 1837 by builder Jan Ripota. Its two street facades, the western one on Prvního pluku facing the Negrelli Viaduct and the southern one on Křižíkova, are each seven axes wide, divided by cornices and tall pilasters running through the first and second floors.

The house was built in 1837 as a classicist corner building by builder Jan Ripota and received cultural monument status in 1964. The building's history reflects how Karlín developed during the 19th century.

The house stands on a corner where Prvního pluku meets Křižíkova, but both streets postdate it: the building went up in 1837, Křižíkova was only formed in 1884 and the Negrelli viaduct built 1846–1849. Its late-classicist facades, seven axes wide, are divided by cornices and tall pilasters running through the first and second floors.

Access to the building is easy to spot at the corner of two streets, making orientation straightforward. Visitors should note that this is an active residential building, so only the exterior can be viewed.

The house predates both Křižíkova Street, created in 1884 by joining two older sections, and the Negrelli Viaduct, built between 1846 and 1849. Its western facade on Prvního pluku faces the viaduct directly. Between 2020 and 2024 the building was renovated and a rooftop flat with an outdoor atrium was added, designed by architect Petr Jančálek.