The small village of Giverny is about an hour away by car from central Paris (I am not aware of any public transportation options to get there, but there are surely organized bus tours from the city).
Its main attraction is Claude Monet House and Garden ♥♥♥. The Impressionist master’s estate is well worth the trip, although organization is a bit disappointing: there is one single ticket counter at the entrance that causes a long wait if you don’t buy tickets in advance; with many paths in the garden being off limits, hundreds of visitors inside at any given time make the place extremely crowded.
But the garden is beautiful, and the famous lily pond is just incredible! The house itself is interesting enough and offers an unexpected bonus of hosting a small collection of Monet’s paintings inside. The souvenir shop is big and pretty interesting on its own merit.
There is also an Impressionist Museum in the village that did not fit into our schedule. Many artist galleries on the main street contribute to the feeling that Giverny can easily sustain a half-day visit (aside from Monet’s house, nothing is too crowded).
Also…
If you come on Saturday, start your day with a visit to nearby Vernon for a market ♥♥. It takes over several main squares in town and is simply delightful. There is tons of food, clothes, crafts, etc. On our visit in 2018, due to some festival, part of the market was Medieval, offering traditional crafts.
The town itself may not be too remarkable, but there is a castle and a cathedral, largely obscured by market stalls.
Halfway between Giverny and Paris, in Poissy, we stopped by to take a look at Villa Savoye ♥, one of the signature creations of Le Corbusier. This is a stop for enthusiasts of modern architecture or for World Heritage chasers. The innovative design concepts are dulled by the fact that the building sits practically empty.