BANGKOK — Thailand's 85-year-old king on Thursday left the Bangkok hospital where he lived for the past four years and returned to his seaside palace with the queen.

King Bhumibol Adulyadej and Queen Sirikit traveled by car to Klai Kangwon Palace in the town of Hua Hin, where they lived before the world's longest-reigning monarch was hospitalized with lung inflammation in September 2009.

Tens of thousands of well-wishers gathered in front of Bangkok's Siriraj Hospital to see the widely revered Bhumibol off.

Sitting in a Volkswagen van, the king looked fresh in his patterned shirt and salmon-colored suit. The queen was wearing a bright blue top and a pearl necklace. Both waved eagerly to the crowds of people who waved pictures of the king, as well as the Thai and royal flags.

"As a Thai, I'm here today to see him off," said Poranee Sunasuan, a 39-year-old officer worker from Bangkok. "I feel so good that I can't describe into words. I'm really happy to be here."

Throngs of Thais also welcomed the king near the royal residence in Hua Hin, a seaside town in the southern province of Prachuap Khiri Khan, about a 2 1/2-hour drive from Bangkok.

The palace has not indicated whether the king's move will be permanent.

Bhumibol has had a variety of ailments and almost disappeared from public life after being hospitalized for what the palace called a lung inflammation. He made only rare day trips, always in a wheelchair.

The 80-year-old queen was admitted to the same hospital last year after the palace said she experienced dizziness and staggered slightly while walking for exercise.