National road N-623
Carretera nacional N-623
Route information
Length	153 km (95 mi)
Major junctions
From	Burgos
To	Santander
Location
Country	Spain
Highway system
Highways in Spain Autopistas and autovías National Roads

The N-623 is a highway in northern Spain. It connects Burgos with Santander.

It starts at Burgos on the Autovía A-62 and a junction with N-I. It passes through the city over the River Arlanzon. It then heads north having a junction with the N-627.

The road then climbs to cross the Puerto del Paramo de Masa and then Portillo del Fresno (1,050 m). The road then winds down to the Upper Ebro valley. There is a junction with the N-232 at the eastern edge of the Embalse del Ebro. The road then climbs again into the Cordillera Cantabria crossing Puerto del Escudo (1,100m). Continuing along a narrow valley the road reaches the N-634. Thereafter, the road turns north east towards Santander and a junction with the Autovía A-67.