Finsbury, Clerkenwell and Bloomsbury are all interesting areas to explore if you appreciate history and old buildings. I wouldn't aim for riding circuits on the main roads though. It's much more pleasant to just have a nice random pootle down all the back streets and little alleys, just making it up as you go. The only great thing about the virus situation is the traffic is down to post-Christmas levels, but without the cold crappy weather, so I have been out several times in the last week after finishing work.
This is actually similar to my route as im from the Harringay area - though i cut through turnpike lane before Finsbury park, then onto holloway road, old street - swing back around to Angel Islington for a 5min breather then back home almost the same way. shooting straight down seven sisters road instead of returning to turnpike lane. Its roughly around 16miles.
its got a few small inclines, lots of starts and stops (due to traffic lights) and straights where you can absolutely bomb it if you have the energy. Im not so much for exploring - Id rather just get it over and done with so i can get home, have a shower and relax
This is the second day ive stayed at home and did a little weight training instead. Ive been doing my route since saturday and my legs havent been able to keep up with the energetic pace where my mind is at.
The spirit is willing but the flesh is weak.
Lots of options for routes. You could even cut through stoke newington then shoot straight across to regents park from old street. half loop regents park, exit at camden town then decide where else to go.