Because the place is called Seidamari Plaza, this gate is called Seidamari no torii (the gateway of Seidamari). This torii marks the entrance to the sacred area, and before reaching the shrine, which is inside a closed area, there are two more such torii gates.
EXIF info:
Nikon Df
Lens: 24-70mm F/2.8G
Focal Length: 38mm
Aperture: F/6.3
Shutter Speed: 1/400s
ISO Sensitivity: ISO 400