A few minutes drive or a walkable distance away is Wakes Colne. We've been there, it was awesome. It's got a viaduct and a really nice pub called The Swan Inn with garden views of the viaduct. The food is amazing!!
Colchester zoo is about 30 mins down the road. I haven't been yet but Caroline says it is very good and it is on my to do list. While you're there you can pop by her house as she's only just down the road!
I couldn't enter "Colchester" by itself somehow :D So no, that is not a photo of the castle, that is just somewhere I walked in Colchester. The castle is also lovely, as is most of the city. Definitely reccomend a visit.
You can go and visit Caroline and Kieran at their flat in Colchester. It's a very nice flat. 10/10 would visit again to steal the Google home stand they have, it's so cool.
Battlesbridge is south down the A12 and come off towards our house in Rayleigh. Anybody headed back to Romford will sort of go past it and its so cool. There's an antiques centre in an old granary and lots of other antiques places nearby. There is also a very cool shop selling geeky things in the same area. Lovely afternoon out strolling to see the sights and shops. There's also a great pub called The Hawk and its Sunday roast is top notch.