Framlingham Castle is the Norman fortress that gives the town its skyline. The earliest reference dates from 1148, though some academics argue the structure may be as old as the eleventh century. It is built on the curtain-wall plan - thirteen towers linked by a continuous high wall, with no central keep - and the wall walk is still continuous, letting visitors walk the full perimeter as the castle's defenders did. The Howard family, dukes of Norfolk, used Framlingham as their East Anglian headquarters for generations. Thomas Howard, 2nd Duke of Norfolk, who held office under four kings, died here in 1524. When Mary Tudor arrived to claim her throne in July 1553, it was the natural place for her to muster. English Heritage manages the castle now, and the adjacent mere - the artificial lake that once supplied the castle's fish ponds - is maintained as a nature reserve by the Suffolk Wildlife Trust. A nature walk runs through woodland around the water; the meadow next to the castle holds outdoor performances and picnics in summer.

The Church of St Michael the Archangel dates from the twelfth century, with the main rebuilding carried out in the late fifteenth and sixteenth centuries. Inside are eight bells dating from the fifteenth to the twentieth century - a slow accumulation of bronze whose oldest survivors have been ringing for changes since well before the Reformation. The church also contains a very rare Thamar organ - one of the few seventeenth-century English organs to retain substantial original material, named for its builder Thomas Thamar. Most remarkable, however, are the tombs of the Howard dukes. The Howards moved their family tombs to Framlingham from Thetford Priory in the 1540s after the Dissolution destroyed the priory church, and the resulting collection of Renaissance funerary sculpture - including the tomb of Henry FitzRoy, illegitimate son of Henry VIII - is one of the most important in any English parish church. The church and surrounding town features as a setting in Anthony Horowitz's novel Magpie Murders.

Framlingham has the two oldest functioning Post Office pillar boxes in the United Kingdom. Both date from 1856, the early days of the British public letter-posting system. They stand on Double Street and on College Road, painted the standard red, marked V. R. for Victoria Regina. People still post letters in them every day. Around the corner is one of the smallest houses in Britain - the Check House, a former bookmaker's office in the Mauldens Mill Estate that has been converted into a two-storey residence of less than twenty-nine square metres. The ground floor measures twenty feet by seven. Framlingham was named the best place to live in Britain in a national property survey in the 2010s, and now operates as a Fairtrade Town with a conservation area covering its medieval and Georgian core. The town has appeared in numerous TV productions, most prominently as the main setting for the BBC comedy series Detectorists - the Castle Inn pub features as the 'Two Brewers' in the show. The annual sausage festival in October closes the town to traffic and brings butchers from across the surrounding villages to compete for the trophy of best sausage.

Framlingham has produced a remarkable run of musical voices for a town of just over four thousand people. Ed Sheeran, born in 1991, attended Thomas Mills High School - a state secondary school dating from 1751, which is considerably older than the more famous Framlingham College of 1865. His hit single 'Castle on the Hill' is explicitly about driving the road back to Framlingham as a young adult, with the castle visible from the A1120 as you approach. The classical soprano Christina Johnston, born 1989, grew up in Framlingham and attended Framlingham College. The crossover soprano Laura Wright, born 1990, also grew up in the town. The soul singer Alice Russell, born 1976, did too. Earlier in the town's history, Edmund Goodwyn (1756-1832), born in Framlingham, became the physician who first described the diving reflex - the mammalian heart-rate slowing that happens when the face is submerged in cold water, a reflex still studied in cardiology and used in modern emergency medicine. The Earl of Wilmington's title was held by a Suffolk family with deep Framlingham ties. The Massachusetts Bay Colony magistrate Thomas Danforth and the Puritan poet Samuel Danforth were both born in Framlingham in the 1620s, before emigrating to New England.