It is one of the city’s five Etruscan gates, and is original up to the springer of the arch, altered in the 14th century into an ogival one. Oriented towards lake Trasimeno, that gives the gate its name, it is also known as Porta di San Luca due to its proximity to the church by the same name, or Porta della Luna. Above the keyarch, on the outside, is carved a Golgotha and a little way lower a half-moon (variably interpreted to be a symbol of the Crusaders, of the Templars or of the star opposite the sun). On the corbel of left side is a travertine lion (or a Sphinx). It bears traces of letters attributable to the Latin inscription AUGUSTA PERUSIA - COLONIA VIBIA.