Fly from San Francisco to Lisbon for $510 round-trip on United/TAP Portugal.
Seen below, we found seats departing SFO on Monday, May 1, returning from LIS on Tuesday, May 9.
Other dates are also available for travel in late spring/fall.
See our fare details for booking info.
Need a room in Lisbon? Here's what's available for the above dates on Hotelwatchdog.