American homebuyers are searching for bargains in the U.K., as a weaker pound contributes to double-digit price cuts.

The fall in the British currency, which is off 17.5% against the U.S. dollar year to date, has made U.K. real estate cheaper for buyers paying in U.S. dollars. Prices in London are down nearly 20% over the past year on price declines and currency impact, according to real estate broker and advisory firm Knight Frank.

Brokers and real estate experts say the drops have created a rare investment opportunity for Americans to buy into the U.K. market — whether it’s a $400,000 London pied-a-terre or a $30 million historic estate in the countryside.

“We’ve seen a steady increase from Americans,” said Paddy Dring, global head of prime sales at Knight Frank. “There are those who are forwarding their plans, and will use this opportunity for their longer-term investment plans to diversify abroad.”

Knight Frank said the combined price declines and currency drops have created an effective discount of 19% in London’s sought-after Chelsea neighborhood and 17% in Knightsbridge.

When compared with 2014, when the British pound was equivalent to $1.71 and real state prices in London were 13% higher, the discounts are even greater, at over 50% in the Chelsea, Knightsbridge and Notting Hill, according to Tom Bill, head of residential research at Knight Frank. The neighborhoods of Kensington and Mayfair have seen discounts of over 45%.

A property listed at 5 million pounds in Knightsbridge, for instance, would have cost $8.6 million eight years ago but $4 million today.

The savings are even larger on the biggest and most expensive estates. Steve Schwarzman, the billionaire CEO and chair of Blackstone, just bought a 2,500-acre historic estate in Wiltshire County, about 90 miles west of London, for 80 million pounds. The drop in the sterling meant he may have saved up to $20 million or more on the purchase compared with last year.

Dring said American buyers run the spectrum — from older couples looking for smaller apartments, to families looking at studios for a son or daughter attending school in the U.K., to the ultra-wealthy looking for rare properties that make for good long-term investments.

“We don’t see much pure speculation,” he said. “The buyers are usually driven by a business or education or lifestyle.”

But the supply of homes throughout the country is scarce, especially for history country estates, Dring said.

For those with money, though, the savings can be substantial. Brokerage Savills just listed one of the U.K.’s most historic properties — a 1,922-acre estate in the English countryside called Adlington Hall. The property spans six farms, over 20 residential buildings, an event space and a village hall. It was once owned by the British Crown and has been in the same family for over 700 years.

The asking price: 30 million pounds, or about $33 million with today’s currency exchange rates. That marks a savings of more than $6 million for U.S. buyers, paying in dollars, compared with a year ago.