stepped gables are typical of Denmark and are found on smaller churches as at Horne Church, Søborg Church, and Aa Church, Bornholm where the tower has paired crow-step gables at each side. In Denmark the west tower may extend across the whole width of the church, forming a westwerk as at Aa Church and Hvidbjerg Church, Morsø, with some such towers incorporating a large open archway with stairs such as at Torrild Church. Small stone churches in Norway and Sweden have a short wide nave, square chancel, an apse and a western tower with pyramidal shingled spire, as at Hove Church, Norway and Kinneveds Church and Våmbs Church, Sweden. Large central towers occur in Norway, as at Old Aker Church. Free standing belltowers are found, often with half-timbered upper sections. Stone churches, such as Aa Church, Denmark and Lund Cathedral, Sweden, have Lombard bands and paired windows, similar to churches of Lombardy and Germany. Openings are generally small and simple. Many doors have a carved tympanum as at Vestervig Church and Ribe Cathedral, Denmark Most churches have timber roofed naves, but ribbed vaulting over smaller spaces such as the chancel is common. Some small churches, such as Marka Church in Sweden, have groin vaults. Larger churches such as Ribe Cathedral are vaulted. Arcades may be of simple rectangular piers such as at Ribe, Denmark, or drum columns such as at Stavanger Cathedral, Norway. Lund Cathedral has alternating rectangular piers and piers with attached shafts which support the vault. Fully developed Romanesque arcades of three stages occur in churches built under English or German influence as at Nidaros Cathedral, Trondheim. Large churches may have paired towers at the western end, as at Mariakirken, Bergen. Visby Cathedral and Husaby Church, Sweden, both have a tall westwerk, framed by round towers. At Ribe Cathedral the stone westwerk is framed on the south by a Romanesque tower of German form with a Rhenish helm spire and on the north by a taller Gothic tower in red brick. Notable examples Hopperstad Stave Church, Vikøyri, Vestland, Norway (1130) Borgund Stave Church, Borgund, Vestland, Norway Aa Church, Aakirkeby, Bornholm, Denmark (late 12th century) Bjernede Church, Sorø, Zealand, Denmark Østerlars Church, Østerlars, Bornholm, Denmark Horne Church, Faaborg, Funen, Denmark Vestervig Church, Vestervig, Jutland, Denmark Roskilde Cathedral, Roskilde, Zealand, Denmark (1160–1280) St. Bendt's Church, Ringsted, Zealand, Denmark (1170) Ribe Cathedral, Ribe, Jutland, Denmark Old Aker Church, Oslo, Norway (1080)