Belle Isle Aquarium to reopen with new improvements following pandemic closure Historic Albert Kahn-designed building has been closed since March 2020. Tags: Belle Isle Aquarium to reopen with new improvement following pandemic closure DETROIT – The Belle Isle Aquarium is expected to reopen July 16 after closing when the COVID pandemic began. Designed by famed Detroit architect Albert Kahn, the Belle Isle Aquarium opened in 1904. It is the oldest aquarium in the country. The Belle Isle Conservancy has invested $1.2 million in improvements to the aquarium during the closure that upgraded exhibits, new creatures, stabilized life support systems and more. During the 16-month closure, special attention was made to keep the animal life healthy, happy and engaged. An aquarist -- who is also an animal behaviorist -- worked to keep the animals busy so they would languish or get depressed.