(650 ft) gorge. The Aare narrows from its previous width of about to a mere . It is along this gorge that the historic center of Brugg formed near the old bridge, with sections of the old town developing on both banks. Today the southern bank is heavily built up and is composed primarily of residential and industrial buildings, while the northern bank, due to the lack of space at the foot of the Bruggerberg (, is less settled. The Aare broadens again after it exits the gorge and departs the old town, where it flows alongside the Aufeld plain. A majority of the population in this area is concentrated in a small band along the southeastern slope of the Bruggerberg. On the eastern border of the municipality three of the most important Swiss rivers flow together, first the Reuss and the Aare, the combination of which is met approximately further downstream by the Limmat. In the northeasternmost part of town, nestled between the mouth of the Limmat and the Reinerberg ( is the village of Lauffohr, which also is a part of Brugg. Brugg has an area, , of . Of this area, or 13.3% is used for agricultural purposes, while or 28.4% is forested. Of the rest of the land, or 50.2% is settled (buildings or roads), or 6.8% is either rivers or lakes and or 0.5% is unproductive land. Of the built up area, industrial buildings made up 7.9% of the total area while housing and buildings made up 24.1% and transportation infrastructure made up 14.7%. while parks, green belts and sports fields made up 3.1%. 27.9% of the total land area was heavily forested. Of the agricultural land, 8.3% is used for growing crops and 4.0% is pastures, while 1.1% is used for orchards or vine crops. All the water in the municipality is in rivers and streams. Brugg is bordered by the municipalities of Rüfenach and Villigen to the north; Untersiggenthal and Gebenstorf to the northeast; Windisch and Lupfig to the east; Hausen, Habsburg, Holderbank, and Veltheim to the south; Villnachern and Schinznach to the west; and Riniken and Bözberg to the northwest. Over time the built-up areas of Brugg have grown into the neighboring communities of Umiken and Windisch. Enlargement of the municipality Up until the 19th century Brugg consisted of only one-tenth of its current surface area. The municipality's expansion began in 1823