Gosseau's plan left space for churches to be built where mosques had once stood. Initially, converted mosques were used as churches, but Franciscans started to build a Baroque church in 1709 and it was consecrated in 1732. A Franciscan monastery was built between 1699 and 1705, with a new wing being added between 1731 and 1733, which subsequently became a new monastery in 1761. In 1725, the Jesuits commenced construction of the parish church of St. Michael (), following the construction of their own monastery. This church was in use after 1734, despite being incomplete. A Holy Trinity column was erected in the fort's main square in 1730 as a plague monument featuring volutes with pedestals on which four protectors against the plague are placed. Four additional pedestals were added to the monument in 1784, each featuring a statue of a saint. Tvrđa had street lighting as early as 1717. The first system to supply public water in Croatia was opened in Tvrđa in 1751.