The very popular and very Instagram-worthy "firefall" phenomenon is expected to return to Horsetail Fall in Yosemite National Park this month — and its popularity has led to parts of the park needing to be closed to vehicle and pedestrian traffic.

The phenomenon, which recurs in the last couple weeks of February on clear and sunny days, involves a certain angle of the setting sun hitting the waterfall — which only flows in the winter months — at the right angle. The backlit water looks like falling fire or golden lava, hence the name, "firefall."

You've likely seen photos, especially in the last few years, on social media.

As Bay Area News Group reports, multiple areas and roadways in the park will be closed, since a lot of tourists flock to see this sunset phenom.

The dates may shift due to conditions, but as of now, the following closures will be in effect starting Monday, February 7 from noon to 7 p.m., through February 28.

And they've provided a handy map:

Per the news group:

Southside and Northside drives (red lines): Vehicles will be allowed on the one-way loop (eastbound on Southside, westbound on Northside) but they will not be allowed to park, stop or drop off passengers on much of the loop. Pedestrians will not be allowed on or next to Southside. One lane of Northside will be for pedestrians only.
Between Merced River and Southside (red tone): Between Cathedral Beach and Sentinel Beach, this area is closed to everybody. The closure includes the river itself.
Parking will be available in the four lots indicated by purple dots. From the lot near Yosemite Valley Lodge, people can walk 1½ miles on Northside to El Capitan Picnic Area (yellow camera icon). From two of the farther lots, they can take a shuttle to the lodge and then walk the rest of the way.

As SFist reported last year, the peak days for the "firefall" are likely February 12 to February 24, or thereabouts — and peak time will be about 15 minutes before sunset, which during the latter part of February will be between 5:36 p.m. and 5:51 p.m.

Photo by AaronP/Bauer-Griffin/GC Images