THE lights at Edinburgh Castle will be switching off for the first time in five years tonight and for a very important reason.

The impressive fortress, which has long been an iconic symbol for the Scottish capital, will disappear from Edinburgh's skyline for an estimated two to three hours.

If you're wondering why the castle will be going dark tonight, here is everything you need to know.

The special reason why the lights at Edinburgh Castle are being switched off tonight

Edinburgh Castle is expected to re-open to visitors on ThursdayEdinburgh Castle is expected to re-open to visitors on Thursday (Image: Getty Images) The switch-off is part of planned repairs to the castle which will see it lose mains power for an estimated two to three hours from 5pm on Wednesday, October 23.

The last time power was switched off at Edinburgh Castle was in 2019 when electrical LV feeder pillars were installed.

This time, the power will be temporarily switched off to allow essential repairs to the high-voltage cable trays and brackets.

The trays and brackets have reportedly corroded (in part) because of the increased temperature and humidity experienced in Edinburgh in recent years.

Edinburgh Castle and other sites have experienced excellerated corresion Edinburgh Castle and other sites have experienced accelerated corrosion (Getty Images)

Recommended Reading: 

Edinburgh Castle in embarrassing Scottish king blunder

Castle on North Coast 500 branded Scotland's ultimate 'hidden gem'

Anger as Edinburgh student paper accused of anti-Scottish discrimination

The repair works at Edinburgh Castle are expected to finish that same evening with the castle reopening to visitors at normal from 9:30am on Thursday, October 24.

According to Historic Environment Scotland, the organisation which takes care of Edinburgh Castle, a number of coastal properties like Skara Brae and Tantallon Castle have "experienced accelerated wear and tear on their fabric due to the increased moisture and extreme weather conditions brought about by climate change".

The preservation body added that it is tackling this challenge through a "systematic inspection and programme of conservation work of the masonry across all sites".