The floor plan of a church by this artist consists of a hexagon formed in a six-pointed stars, with the points alternately replaced by circles or concavities.
An early work by this artist found at the Vatican was a mountain-shaped fountain with five bees which serve as spouts, the Fontana delle Api. This artist mounted icosahedra onto shortened double-scroll volutes that he borrowed from Michelangelo's Porta Pia atop an altar in Naples's Church of Santi Apostoli, the Filomarino Altar. The floor plan of a church by this artist consists of a hexagon formed in a six-pointed stars, with the points alternately replaced by circles or concavities. This artist reused that Porta Pia motif on the piers of the buttresses of a dome he designed for that church which is topped by a lantern featuring a spiral ramp leading up to a globe and cross. The facade of a church designed by this architect for the Spanish Trinitarians in Rome features a pattern of concavities and convex projections in the form of a double-S curve. For 10 points, name this architect of the Church of St. Ivo della Sapienza and the Church of San Carlo alle Quattro Fontane. 
An early work by this artist found at the Vatican was a mountain-shaped fountain with five bees which serve as spouts, the Fontana delle Api.
Francesco Borromini 