Saint Anne of the Pontifical Grooms

The Church of Saint Anne in the Vatican, known as Sant'Anna de' Palafrenieri, is a Catholic parish church dedicated to Saint Anne in Vatican City. The church is the parish church of the State of Vatican City and is placed under the jurisdiction of the Vicariate of the Vatican City and is located beside the Porta Sant'Anna, an international border crossing between Vatican City State and Italy.

Commissioned by the Venerabile Arciconfraternita di Sant'Anna de Palafrenieri, Giacomo Barozzi da Vignola introduced the oval plan to church design, for the first time in the churches of Sant'Andrea in Via Flaminia and Saint Anne in Vatican, pioneering a plan which was to become influential to Baroque architecture.

Source: Wikipedia