The Tulip Festival is a must-see.

Here are some free local events to mark down on your calendar for April. Go, mark them down now!

The Bloomingdale History Group is sponsoring a special talk by Thomas Mellins, an architectural historian and curator of the recent Affordable Housing exhibit at the Museum of the City of New York, about housing legacies on the West side. It’s on April 4 at 6:30 p.m. at Hostelling International (891 Amsterdam Ave, 103rd St). Learn more here.

The Mannes Orchestra is putting on a free concert of Arvo Pärt’s Symphony No. 3, and Anton Bruckner’s Symphony No. 9 in D minor at Alice Tully Hall on April 8. “Known for their bold and adventurous programming, David Hayes and The Mannes Orchestra have been hailed by The New York Times for playing with ‘inviting warmth and solidity,’ and for their ‘intensity of focus.'” You can pick up free tickets at the box office. More here.

Sandsational, a community event where children and adults volunteer to help move sand into Riverside Park’s playgrounds, will be on Saturday, April 9. More here.

Symphony Space’s Bar Thalia will host free jazz on Sunday April 10 and April 24 with the The New York Jazzharmonic trio. More here.

The Tulip Festival returns this month to the West Side Community Garden on 89th street between Columbus and Amsterdam. The festival will highlight more than 13,000 tulips and other flowers. There will also be tours and live piano music. It runs on the weekends of April 17-18 and April 30-May 1. More here.

Actress Jane Krakowski will give a free talk at the David Rubenstein Atrium on April 25 at 7:30 p.m.. More here.

And as always, check out our weekly events calendar for dozens of local events every week.

Correction: we initially had the wrong date for the Mannes concert.