To all Buddhists Vesak is of special holy significance and is celebrated at full Moon in May.
This particular full Moon is associated with the following events:

The Buddha's birth as Prime Siddhartha took place on this day at Lumbini in Kapilavatthu (modern Nepal) in the year 623 B.C.

Siddhartha Gautama attained suprime enlightenment on this day at Buddha Gaya under the sacred Bodhi Tree.

The great demise of Buddha took place on Vesak full Moon at Kusinara, when he was 80 years old.
His last advice was: "All component things are subject to change. Strive on with diligence".

In order to celebrate this day together with all Buddhists in Copenhagen/Denmark, Buddhistisk Forum took initiative 4 years ago to arrange an open meeting in a park in Copenhagen.
At these meetings it is now a tradition to recite the Heartsutra.
As you can see from the photos, there have been quite a lot of attendants.