The best things to do in Boston this weekend: July 18-20

It’s lights, camera, action as the Prudential Center’s annual summer outdoor movie series continues on July 19 with its screening of the blockbuster 13 Going on 30. Hosted in the South Garden, the movie begins at dusk, but there is music entertainment starting at 6:30pm.

Join the summer fun by the Harbor on July 19 from 12-4pm at the The Institute of Contemporary Art (ICA)'s Watershed Block Party - a free event featuring music, art, games, and more held at the museum's  seasonal space located in the East Boston Shipyard and Marina. The first of two held this summer (the second one is on Aug. 16), the afternoon includes beats by Sonido Social, tasty bites for purchase by Aloe Natural Açai & Coffee Shop, dance performances and face painting by Veronica Robles Cultural Center, art-making by Postcard Stories, corn hole, sidewalk chalk, and much more.

The locally grown alternative rock band, the Pixies, are giving Boston two special nights of music. They'll perform with with guest Momma on July 18  and July 19 at 8pm with guest Kurt Vile + The Violators at the MGM Music Hall at Fenway Park.

Tom Hanks narrates an epic experience that offers a unique new perspective on humankind's past and future voyages to the Moon. This new in-person immersive cinematic experience by Lightroom and Paquin Entertainment Group is opening June 27 at The Saunders Castle at Park Plaza and will serve as the first stop of the North American tour of The Moonwalkers: A Journey with Tom Hanks. The 50-minute show transforms the venue into a spectacular voyage to the Moon, combining powerful storytelling, rare NASA archival footage, and cutting-edge spatial audio to bring the gripping stories of the Apollo missions to life.

From jazz to soul, country to R&B, and even DJs, Boston’s favorite free water-side concert series - Summer in the City Entertainment Series – returns for its 25^th season at the Boston Harbor Hotel. Running Tuesdays through Fridays from June 12 through Aug. 28, the Boston Harbor comes alive with bands performing nightly on the hotel's floating barge stage with the sunset over the Atlantic Ocean as their backdrop. Enjoy smooth sounds and salty air, with shows from 6-10pm. New this year is the expanded bar, a revamped menu of shareable bites, and pop-up experiences. Check here for the lineup.