Genius Gems

Genius Gems offers open play with magnetic tiles, the Design Bar, robot stations, and challenges with prizes. It also offers weekly coding, robotics, engineering, and design classes, full-day STEM mini camps on school-closed days, weekly summer camps with a new project every day, birthday parties with a private room and host, and drop-off evening Date Night with building, pizza, and a movie.

Programs

• General Admission / Open play — Ages 4 and up with a grown-up · $15.99–$29.99 · Open play with magnetic tiles, Design Bar, robot stations and challenges with prizes. Two locations: Millburn, NJ and Chelsea, NYC.
• After-school classes — Grades Pre-K–6 (Pre-K in Millburn) · Once a week · Weekly coding, robotics, engineering and design classes; school pickup where offered. 45 minutes.
• Mini camps — Grades K–6 · On school-closed days · Full-day STEM camp on days school is closed. Book one day or several.
• Summer camp — Grades K–6 · Weekly all summer long · Weekly themed camp all summer long with a new project every day.
• Birthday parties — Ages 4–12 · Private room, a host, and the whole play space.
• Date Night — Grades K–6 · Evening · Drop-off evening of building, pizza and a movie.
• Field trips — Hands-on STEM visits for schools, camps and groups.
• Scouts — Badge-earning coding and engineering events for troops.
• After Dark — Adults · Team-building and private events for adults, plus the AI Flavor Lab.
• Kids' STEM Classes — Pre-K–6th grade (Pre-K in Millburn) · Once a week, 45 minutes · Weekly STEM classes taught by the Genius Gems team; topics include design, engineering, chemistry, robotics and coding.

At a glance

• Ages: 4–16 years old
• Price range: $15.99–$29.99
• Current session: Winter 2027 semester (Millburn, NJ) (Jan 5–Apr 9, 2027); Winter 2027 semester (Chelsea, NYC) (Jan 4–Apr 21, 2027)
• General schedule: After-school classes: once a week, 45 minutes. Mini Camp: school-closed days. Summer camp: weekly all summer long. Date Night: evening.
• Facility hours: Mon-Fri 1:00 PM-5:30 PM; Sat-Sun 10:30 AM-5:30 PM

About the provider

Genius Gems first opened in Millburn, NJ in May 2018, and the NYC flagship followed in February 2023. Founder Jennifer Romanoff, Ed.M., started Genius Gems in 2013 after watching her husband and two boys building with magnetic tiles. Its mission is a hands-on STEM play space built around the idea that kids learn best when they can hold what they are learning.

Every visitor needs a ticket, including adults, and there are no door sales. Two locations, each with its own hours, tickets, classes and camps. Mini Camp campers must be age 5 and up, in Kindergarten or older, and fully toilet-trained. Pack a labeled lunch, a snack and a labeled reusable water bottle; NYC pizza lunch and after-care are available at extra cost. Mini Camp days are booked separately. Sales tax and a 3% card processing fee are added at checkout.

Last updated October 19, 2026.