Where is Queen Jane Seymour buried?

She was buried in the Frogmore mausoleum which is in the park system of Windsor Castle. She died in the Osborne House on the Isle of Wight.

She is still buried in the Frogmore, Windsor, Berkshire
Queen Victoria lies buried in the mausoleum- with her husband- Prince Albert called Frogmore. This is in the so-called Home Park of Windsor Castle. Victoria is not- and never was buried in Westminster Abbey, where Five Sovereign and several consort Queens are interred.