The larger towns on the island are located on the coast and have harbours. There is however one exception, centrally placed Aakirkeby, which was also the name of the municipality from 1970 until 2002, which did, however, include the harbor, Boderne, 5 kilometres (3.1 miles) to the south. The largest town is Rønne, the seat, in the southwest on the westernmost point of the island. The other main towns (clockwise round the island) are Hasle, Sandvig, Allinge, Gudhjem, Svaneke and Nexø. Monday morning 22 September 2014 it was documented by Folkeregistret in the municipality that the number of people living in the municipality that day were 39,922, the lowest number in over 100 years.
The town of Rønne after the merger of the island's administrative entities 1 January 2003 reached a low point of 13,568 inhabitants 1 January 2014. 15,957 people in 1965 lived in the two parishes that would become Rønne municipality from 1 April 1970. In the table, numbers for Rønne are for the parish of Rønne, Rønne Sogn, alone. Year unknown, but between 2000 and 2005. It does not include Knudsker Sogn, which was also a part of Rønne Municipality. Other localities (with approximate populations, not updated) include Aarsballe (86), Arnager (151), Olsker (67), Rutsker (64), Rø (181), Stenseby (?) and Vang (92). In 2010 and 2018 10,297 and 9,111 respectively lived in rural districts, and 88 and 71 had no fixed address. A rural district is defined by Statistics Denmark as a settlement with less than 200 inhabitants.
Population numbers are from 1 January. Christiansø Parish (which encompasses Ertholmene) is not a part of Bornholm Regional Municipality. It is included because Danmarks Statistik includes it as parish number 7568. Bornholm has 21 parishes (2018) that before 1 April 1970 were parish (15) or market city (6) municipalities themselves. There are 2,158 parishes (2021) in the Church of Denmark.
On the surface of Bornholm older geological formations can be seen better than in the rest of Denmark. Stubbeløkken – which is still operating (Danish i drift) – and Klippeløkken granite quarries in Knudsker parish just east of central Rønne – and statistically a part of the town – are among the few remaining quarries of what was once many active quarries on the island. The island's varied geography and seascapes attract visitors to its many beauty spots from the Hammeren promontory in the northwest to the Almindingen forest in the centre and the Dueodde beaches in the southeast. Of special interest are the rocky sea cliffs at Jons Kapel and Helligdomsklipperne, the varied topography of Paradisbakkerne and rift valleys such as Ekkodalen and Døndalen. Bornholm's numerous windmills include the post mill of Egeby and the well-kept Dutch mill at Aarsdale. The lighthouse at Dueodde is Denmark's tallest, while Hammeren Lighthouse stands at a height of 85 metres (279 ft) above sea level and Rønne Lighthouse rises over the waterfront.
Examples of roads that have (very) steep climbs and descents are: (inland) Simblegårdsvej in Klemensker, which begins by the village inn Klemens Kro, and Slamrebjergvej just outside Nexø extending northward from the main road from Rønne. Along the coast there are several steep roads, which is also the case in some parts of Denmark as a whole, for instance in and around Vejle.
The island hosts examples of 19th- and early-20th-century architecture, and about 300 wooden houses in Rønne and Nexø, donated by Sweden after World War II, when the island was repairing damage caused by the war. The island is home to 15 medieval churches, four of which are round churches with unique artwork and architecture. The ancient site of Rispebjerg has remains of sun temples from the Neolithic and earthworks from the Iron Age.
There are 14 European bison near Åkirkeby, attracting 100,000 visitors a year.
Bornholm has an oceanic climate relatively similar to southern Sweden and mainland Denmark, whose summer highs and winter lows are heavily moderated by its maritime and isolated position. Even though heat is rare, the climate is sunny during summers and rainfall is generally sparse for a climate of this type. The winter (November–December) 2010 – (January–April) 2011 was exceptionally extreme with snow depth reaching at least 146 cm, 2 inches short of 5 feet (snowdrifts 6 meters, almost 20 feet) the highest in Northern Europe. Military assistance was needed. The DMI estimated the weight of snow to be 100 million ton.
