London, Dublin, Belfast, Edinburgh

Last fall, before driving in Czech Republic, I bought a Garmi Nuvi GPS in the US and then bought a map of Czech Republic for it. That worked out pretty well. You could presumably do the same.

if you have an Android smartphone or iPhone you can purchase an app called CityMaps2Go. It's a map of the city you're visiting that can display your location, hotel, restaurants, etc. without the need for cellular or wifi. It works completely offline. you'll download the maps and points of interest before you go. best $1.99 you'll ever spend

If you have a Nokia Windows phone you can use the free preinstalled apps. Download the maps at home and away you go. Also tells you of places of interest, restaurants etc.

Use Google maps if you have an android phone..works great

doesn't google maps require a connection to google, via wifi or cellular network?

It sounds like safir is looking for a solution that has maps loaded on the phone, can use the phone gps receiver, but does not require connection to google or any other server.

On my Android device I can download and save Google maps for offline use. They work well with the GPS. There is a limit to how many maps and how large each map can be. It worked well for both Paris and Toulouse during my recent trip.

On Android phone with Google maps, menu (...), then "make available offline". You can zoom up/down to capture the area you want to keep offline. You can keep up to 6 offline maps at any one time. The largest map can get around 80MB if you cache the biggest area they let you around major city like Rome, so do it when you have access to fast Wifi. It also takes a long time to delete a map. To see what you have in cache, top left "my places", then slide left to "offline".
If you have marked located in "my maps," the pinned locations are not accessible offline. However, favorite locations (ones you marked by stars *) are downloaded to your phone and are available without internet. So that is how I mark destinations, restaurants, hotels, etc on my phone.