The Canada Science and Technology Museum is one of Ottawa's strongest family-oriented museums and a useful counterweight to the national political and history sights downtown. Its galleries cover Canadian invention, transport, communications, energy, and everyday technology, with enough hands-on material to keep the visit from feeling purely archival.
The museum is east of the core, so it usually needs a deliberate trip rather than a casual walk-by. That effort is worthwhile for travellers with children, science interests, or a rainy day to fill; allow at least two hours if you want to move through the major exhibits without rushing.