Karlskirche, also known as St. Charles's Church, is a baroque-style church located in Vienna, Austria. It was built between 1716 and 1739 under the patronage of Holy Roman Emperor Charles VI to fulfill a vow he made during a plague epidemic.

The church was designed by Johann Bernhard Fischer von Erlach and completed by his son, Joseph Emanuel Fischer von Erlach, after his father's death. The church's design is notable for its massive dome, which is 72 meters tall and features a painted fresco of the apocalyptic Last Judgment.

The church's façade features two columns inspired by Trajan's Column in Rome, and its entrance is flanked by two sculptures of St. Peter and St. Paul. Inside the church, visitors can admire the grandiose Baroque architecture and stunning frescoes depicting scenes from the life of St. Charles Borromeo, the church's patron saint.

One of the most unique features of Karlskirche is its two spiral staircases, which visitors can climb to get a closer look at the frescoes in the dome. The church also houses an elevator for visitors with mobility issues.

Today, Karlskirche is a popular destination for tourists and locals alike, attracting visitors with its grand architecture, stunning frescoes, and rich history.