Im really interested in factories, large factories tend to be located with access to many modes of transportation.
oh yea? well can you tell me a bit about them
Yeah factories have access to rail, highway, and even water loading and unloading facilities.
oh wow i didnt know that
The rail friend transport is really interesting to transport cargo cheaply, considering people think railroads are a thing of the past.
oh cool, what else?
factories manufacture chemicals sometimes but those factories are called plants.
oh yea i know that, makes sense.
Chemical industry
The chemical industry comprises the companies that produce industrial chemicals. Central to the modern world economy, it converts raw materials (oil, natural gas, air, water, metals, and minerals) into more than 70,000 different products. The plastics industry contains some overlap, as most chemical companies produce plastic as well as other chemicals.
Various professionals are deeply involved in the chemical industry including chemical engineers, scientists, lab chemists, technicians, etc. As of 2018, the chemical industry comprises approximately 15%
workshops".
Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production. Large factories tend to be located with access to multiple modes of transportation, with some having rail, highway and water loading and unloading facilities. 
Factories may either make discrete products or some type of material continuously produced such as chemicals, pulp and paper, or refined oil products. Factories manufacturing chemicals are often called "plants" and may have most of their equipment – tanks, pressure vessels