GRAND RAPIDS, Mich. (AP) — Frederik Meijer Gardens & Sculpture Park in western Michigan says it had its busiest summer season for attendance in its 20-year history.

The Grand Rapids attraction announced Wednesday that it had about 280,000 visitors in total in the months of June, July and August.

Meijer Gardens says the opening of its $22 million Japanese garden after years of construction and the acquisition of “Iron Tree,” a large iron sculpture by Chinese artist and activist Ai Weiwei, were among the reasons for this summer’s spike in attendance.

Joseph Becherer, chief curator and vice president of Meijer Gardens, says in a statement: “In this, our 20th year, it is extraordinary to see the development of Meijer Gardens from a regional institution to a cultural organization on the global stage.