On standard tours of St Petersburg, you need to prepare for quite a lot of walking, particularly on cobblestones. Visitors with mobility issue or want to visit venues with good wheelchair accessibility may be daunted. But don't let what happens on standard tours put you off from visiting Russia.
Russian attitudes to disabilities are changing fast. During the Soviet era, the authorities denied that disabled people existed. However, Russia recently hosted the Paralympics, and signed the UN Convention on the Rights of Disabled people. Although some of the infrastructure still has room for improvement, this is a country that's becoming far more aware of the issues faced by people with disabilities.
All tours will be flexible towards people with mobility impairments and disabilities to some extent, although the flexibility may only extend to allowing you to stay on the bus if an attraction isn't suitable. But you didn't come all this way to sit on a bus while everyone else sightsees! Booking a private tour, with a small number of people, will mean that every possible adjustment is made – drivers can park at raised pavements, tour guides will find stair-free routes through Winter Palace, and the day can be shortened if you tire easily.
Generally, attractions with good disabled access, with facilities like escalors, include the Hermitage, the Catherine Palace, Spilled Blood Church, St. Isaac's Cathedral and Peterhof Park. Other churches, palaces and theatres are often mostly accessible, and venue staff or your guide will be able to help you up stairs.
The best tour companies won't see you as a disabled person who has to go on a truncated version of the standard tour. They'll want to work as hard as they can to plan a tour that fits in with your interest, and do their best to overcome any obstacles presented by your mobility impairment or disability.
You can help by booking in advance and giving a clear indication of what you can and can't manage. For example, if you want to see an opera but are worried about being able to climb, your operator will be able to check with the theatre to get you the best possible tickets for seats that are accessible to you. If you can't stand for long periods of time, then a guide can arrange queue jump tickets to big attractions. If you love eating out and need to use a wheelchair for some or all of the time, then let your rep know, so they can research and make reservations at a good restaurant that is accessible.
Russia isn't perfect when it comes to access for disabled people – but most Western countries have only begun to become more aware of disabled issues in the very recent past. You may find that, for example, ramps are steeper, or building doors are too narrow to allow you to pass. Historic buildings aren't easy to adapt, but the people who live and work in Russia now will normally make every effort to help people with mobility impairments. Everyone should be able to enjoy a holiday here.