The waterfront in Liverpool is the centre of things to do and see. Catch the Hop On Hop Off bus there but most importantly see the Liverpool historical museum. Fascinating history of the city revealed. Take a Beatles bus tour from down there, just great, see Aunt Mimi’s house and Strawberry Field.
In Paris, everything touristy is essential. I’d skip Pere Lechese cemetery unless that’s your thing. Keeping close to the river on both sides reveals most of the best of Paris. Skip the inside of Pompidou Centre. Find a small gallery in the suburbs of Monet, among others, paintings. Can’t think of the name but Google will find it.
We found Pritemps, a department store, to be a revelation into what Parisians buy. All nice stuff as it turns out.