US travellers are flocking to the UK because of the soft pound, according to one of the world's largest online travel firms.
Expedia reported an 80% jump in UK summer bookings from across the Atlantic between January and March, compared with the same period last year.
American visitors are taking advantage of the 13% fall in the value of sterling compared with the US dollar since the EU referendum in June last year.
Expedia's global head of transport, Greg Schulze, said: "The best deals on air fares are coming from the US into the UK. We're seeing discounts of 20% to 30% from a year prior."
Demand for US travel to Europe has been "resilient" despite a number of deadly terror attacks, Mr Schulze said.
In an interview with the Press Association, he said: "When there is an incident, travel is impacted. But we've seen it to be quite resilient.
"The reality is that people love to travel. Right now, there are good deals for Europe as a destination, especially the UK as a destination.
"It's largely related to the currency, but also with the capacity for the airlines on certain routes and the competition that brings. We've seen great deals for travellers coming into the UK."
UK hotel and flight packages for US tourists are more than 45% cheaper than last year, Expedia's figures show.
After three years of strong growth, inbound tourism to the US has steadied in recent months, leading to airlines also offering attractive prices for westbound travel across the Atlantic, according to Mr Schulze.
The perception of the US as an accessible destination for visitors "has certainly been impacted" by measures to tighten border controls since Donald Trump's election as president, he said.
"As less people are coming into the United States - we have seen a slowdown of travellers going into the United States - the airlines will adjust pricing to make sure that those planes will continue to be full. Travellers going in both directions are finding terrific deals."
Cross-channel rail operator Eurostar reported earlier this month that it has also seen a surge in the number of American passengers, helping it to reverse a decline in turnover and passenger numbers.
During the first three months of this year, it recorded a 13% year-on-year increase in US customers, compared with an overall rise of just 2%.
Bernard Donoghue, director of the Association of Leading Visitor Attractions, said North Americans view the UK as an "aspirational destination", but it has always been perceived as expensive.
"The fact that we're better value because of the fall in the strength of sterling means that Americans in particular have taken the opportunity of booking here in record numbers," he said.
Mr Donoghue said many US visitors are attracted to the UK's reputation for history and tradition, with the Tower of London, Edinburgh Castle and Westminster Abbey among the most popular attractions.
"I would guarantee that there will be a lot of Americans going to the summer opening of Buckingham Palace," he added.
Latest figures from the Office for National Statistics show that 4.4 million people from North America visited the UK in the year ending March, up 9% on the previous 12 months.