A nice romantic place believe it or not is Jodrell Bank radio telescope visitor centre 20 miles south of Manchester.The Arboretum has 2000 kinds of trees and shrubs and at this time of year they will be looking fab.
There's a cafe with a view right over the huge telescope dish and a load of displays in the techie bit, with 3-D Mars movies and more space bits.
Driving directions are on the website, first link.
Main visitor site below....click on the links for the various bits.
http://www.jb.man.ac.uk/contact/map.html . . . .
http://www.jb.man.ac.uk/visitorcentre . . .
For scenery it would be difficult to beat Ladybower Reservoir for a great place to drive to.
The road out there is brill, terrific views of the reservoir from the tops, and pretty good when you're there. Map on here, and drive the A57 Snake right over Ladybower. What a great test drive for a car. One of the best drives in England, that one.
http://www.lakelubbers.com/ladybower-reservoir-1047