By nature, refineries are huge, heavily-lit spread-out complexes.

Around the globe, a handful of these complexes distinguish themselves through enormous throughput, cutting-edge systems and their strategic role in meeting regional and international energy demand.

A look at 5 of the largest, in size, according to oilandgasclub.com:

Where are the largest oil refineries, by size?

Photograph: Kind courtesy Reliance Industries/Wikimedia Commons

1. Jamnagar Refinery, India

Reliance Industries' Jamnagar facility in Gujarat is recognised as the largest oil refining complex globally, with a combined processing capability of around 1.24 million barrels per day, making it a cornerstone of India's petroleum sector and a major player in the international energy market.

Photograph: Kind courtesy Génesis García/Wikimedia Commons

2. Paraguana Refinery Complex, Venezuela

The PDVSA-run complex is second. State-owned. it is situated on the Paraguana peninsula and the sprawling installation combines the Amuay and Cardón refineries, which together handle roughly 955,000 barrels of crude per day.

Photograph: Kind courtesy Lee Sung Woo/Wikimedia Commons

3. Ulsan Refinery, South Korea

Run by SK Energy it too stands as one of Asia's foremost refining centres, with a processing capacity of about 840,000 barrels per day.

Photograph: Kind courtesy Rickmaj/Wikimedia Commons

4. Ruwais Refinery, UAE

A crucial pillar of the country's oil-processing network, it is operated by Abu Dhabi National Oil Company and the large-scale complex has an output capacity of approximately 837,000 barrels per day.

Photograph: Kind courtesy Carol M. Highsmith/Wikimedia Commons

5. Port Arthur Complex, USA

In Texas and operated by Motiva Enterprises, the complex located on the easternmost port of the state is said to be the largest refining facility in the United States, processing roughly 636,000 barrels per day.