For peak summer travel, fly from Philadelphia to London for $701 round-trip on United.
Searching United.com, we found seats departing PHL on Monday, July 13, returning from LHR on the following Monday, July 20.
Other dates are also available for travel through next October.
Similar fares are available for peak summer travel from Charlotte, Dallas, and Miami. Visit our listings for London LHR for a complete look at current finds.
Need a room in London? Here's a look at what's available on Hotelwatchdog for the above travel dates.
You'll also find rooms going for $158/night at the CitizenM Bankside currently featured on Jetsetter.