Nice enjoys the Mediterranean's dry, clear climate, giving the Côte d'Azur some of the most reliable clear nights in France despite the city's Bortle 7 coastal glow. The Maritime Alps rise steeply just inland, reaching Bortle 3–4 within 40 minutes and Bortle 2 in the Mercantour National Park. The historic Nice Observatory sits on Mont Gros above the city. At 43.7°N, the southern sky is well placed, and the combination of high mountains and dry air makes for excellent transparency. The dark Mediterranean horizon aids low-altitude observing.