About 350 people entered the tower and climbed its historic steps throughout the day. The guard collected about $500 in donations for RCPD.

“The tower was a big source of pride and symbol of learning for MSU back in the day,” said Brendan Mullen, the organization’s historian and a Lyman Briggs sophomore. “This gives people a chance to see what the old campus is all about.”

The tower was finished in 1929 and serves as a marker for College Hall, the first building in the U.S. that was dedicated to scientifically teaching agriculture. It stood from 1856 to 1918.

“I still get chills when I go up there,” said Tower Guard President Mariah Smith, a media and information and communication sophomore. “Every time I walk in, I have to take a deep breath — it’s so surreal … It’s not like any other building on campus.”

The first floor of the tower is home to a practice carillon, a musical instrument that is played by striking keys, which causes clappers to hit the bells. The second floor is the Tower Guard meeting room. The functioning carillon, which consists of 49 bells of varying sizes, is housed on the fourth floor.

MSU’s carillon is one of less than 20 in Michigan and less than 200 in the U.S. The largest bell weighs about two and a half tons, while the smallest is just 15 pounds. The instrument and the interior of the tower were restored in 1996 after it had been silent for almost a decade.

MSU alumnus Andy Elms took a tour after not going inside since he went to MSU and had a friend that took carillon lessons, he said. The friends he was with on Saturday had never gone in.

“It’s just a pretty cool little place — a nice piece of campus that you don’t get to see all the time,” Elms said.

Laura Karrer, a 2012 alumna, took a tour and said she had never been inside before.

“One of the things that I thought was really cool was the big trap door in the floor for when they have to replace the bells,” Karrer said. “They lower them down through the trapdoor. It’s huge, maybe 4 feet by 4 feet.”