Emeritus Pope Benedict XVI is leaving the Vatican for his first sojourn since retiring. He's escaping an impending heat wave by heading to the papal summer residence at Castel Gandolfo.

The 88-year-old Benedict left Tuesday morning for two weeks of vacation at the Vatican estate in the Alban hills south of Rome, where he used to spend holidays and where he lived for several months after retiring in 2013.

The palazzo, overlooking a lake, is ringed by gardens and a working farm.

Pope Francis bid Benedict farewell Tuesday morning. Francis has refrained from using Castel Gandolfo, preferring to spend summer vacations at the Vatican hotel where he lives.

Benedict isn't known to have left the Vatican much since retiring, though he visited his brother in 2014 at a Rome hospital.