queen security
Security barriers placed near to Windsor Castle are seen in Windsor, Britain, March 28, 2017. REUTERS/Peter Nicholls

Last weekend’s terror attack in London led to the police putting up additional security around Queen Elizabeth II’s residence at Windsor Castle, after four people were killed during an attack near the parliament.

Windsor Castle, the “oldest and largest inhabited castle in the world,” is where Britain’s longest reigning monarch spends most of her time. Located around 20 miles west of London, the castle is seeing an overhaul of security after a recent review carried out by the police, Reuters reported Tuesday.

Read: Queen Elizabeth Indulges In Her Favorite Hobby In Windsor Castle’s Grounds

“While there is no intelligence to indicate a specific threat to Windsor, recent events in Westminster clearly highlight the need for extra security measures to be introduced,” Assistant Chief Constable Dave Hardcastle of Thames Valley Police told the publication.

The police has put in place more road closures and erected new security barriers, which could be seen on the streets leading to the castle before the “Changing the Guard” ceremony that was held Wednesday. The castle is a major tourist attraction, bringing over 1.3 million people every year. The Wednesday ceremony, which takes place regularly, also attracts thousands of tourists.

“The force believes that it is proportionate and necessary to put in place extra security measures to further protect and support the public and the Guard Change,” Hardcastle added.

Despite the threat, the queen was photographed enjoying a horse ride, one of her favorite hobbies, Wednesday. The 90-year-old was dressed in a beige coat and matching shawl and was accompanied by two others as she took out a small black horse for a ride in the castle’s grounds.

The Telegraph reported that her husband Philip, the Duke of Edinburgh, was also spotted driving his carriage near the newly installed security barriers as a police officer stood in place to guard the British royalty.