Balboa Park is filled with many treasures but here are a few that just can’t – and shouldn’t – be missed.

The California Tower

One of Balboa Park’s most eye-catching and iconic structures is the California Tower. Constructed for the 1915 Panama-California Exposition, this soaring structure is a hybrid of different architectural styles inspired by the churches of Mexico and Spain. At a 198-feet tall, and more than 460 feet above sea level, the California Tower also offers eye-popping views of San Diego from every vantage point. After being closed for almost 80 years, the tower reopened in 2015 to the public. The Museum of Us offers multiple tours daily. To climb the California Tower, you must physically be able to ascend and descend 125 steps within a 40-minute period, including 10 to 15 minutes on the viewing deck. But have no doubt it is more than worth the effort.

Spreckels Organ Pavilion

You will definitely want to schedule your visit to coincide with one of the many free outdoor concerts at the Spreckels Organ Pavilion, which is home to the largest pipe organ in the world. Donated to the City of San Diego in 1914 for the Panama-California Exposition, the organ has more than 5,000 pipes that range in length from the size of a pencil to 32 feet. Raúl Prieto Ramírez, is the city’s world renowned civic organist, making San Diego one of only two U.S. cities with a civic organist. Ramírez plays as many as 62 free concerts a year, including weekly concerts on Sunday at 2 p.m., with music that ranges from Bach’s Toccata in C to songs from the movie La La Land and the theme to The Pink Panther. It’s certainly a sound to behold.

The Old Globe

Considered one of the finest regional theaters in the country, The Old Globe Theatre was built in 1935 as part of the California Pacific International Exposition and was modeled after Shakespeare’s Old Globe in London. Since then, it has been home to some of theater’s most acclaimed actors, designers, directors and playwrights. More than 20 productions produced at The Old Globe have gone on to Broadway and Off Broadway, garnering 13 Tony Awards and numerous nominations. In 1984, the Globe was the recipient of the Tony Award for Outstanding Regional Theatre for its contribution to the development of the art form. The Old Globe produces a year-round season of 15 productions on its three stages: the Donald and Darlene Shiley Stage in the 600-seat Old Globe Theatre and the 250-seat Sheryl and Harvey White Theatre, both part of The Old Globe’s Conrad Prebys Theatre Center, and the 605-seat outdoor Lowell Davies Festival Theatre, home of its internationally renowned Shakespeare Festival. The Old Globe’s productions are from all periods and styles, ranging from Shakespeare to an ongoing emphasis on the development and production of new works, along with the annual family musical Dr. Seuss’ How the Grinch Stole Christmas!

Botanical Building and Lily Pond

One of the most photographed structures in the park, the Botanical Building and the adjacent lily pond were constructed for the 1915 Exposition. Today the historic building is one of the largest lath structures in the world and includes more than 2,100 permanent plants, featuring fascinating collections of cycads, ferns, orchids, other tropical plants and palms. The Botanical Building also presents some of the park’s vibrant seasonal flower displays and is considered a must-see for visitors.

San Diego Zoo

The world-famous San Diego Zoo is situated on 100 acres on the northeast portion of Balboa Park and is home to more than 3,700 animals from some 650 species and subspecies and its botanical collection includes more than 700,000 exotic plants. The San Diego Zoo was a pioneer in the concept of open-air, cageless exhibits that re-create natural animal habitats and is also a recognized world leader in species conservation.