One route, followed properly: London Gatwick (LGW) to San Juan (SJU), return. What follows is the lowest fare our radar has picked up on it and the precise dates behind that number, rather than a headline price with the conditions left out.
We do not post a price and leave it to age. Each fare is re-checked against Skyscanner on a schedule and carries the time it was last confirmed. Not flying from London Gatwick? We track 32 other departure cities for San Juan, listed at the foot of this page.
Cheap fares do not hang around. If this one has already gone, nudge the dates either way by a day or two; London Gatwick to San Juan is usually still decent value around the same window.