About 1980, the United States Postal Service detached the two-thirds of greater Oxon Hill that was furthest from Washington, D.C. and re-defined that part as a new postal designation, Fort Washington, MD.
A gallon of paint is heavier than a gallon of water. Mostly anything that mixes a solid into the water will be heavier than water. Most homes have a can of Spackle , which is a common liquid for patching drywall and it is almost twice as heavy as water. Of course,mercury is the heaviest liquid, but isn't common around the house anymore. But if you have a mercury switch for turning on your furnace, then that would be the heaviest common liquid by far. Which, I assume, discounts mercury - oil is lighter than water, so two choices would be sugar water or salt water.
Green anaconda. The green anaconda (Eunectes murinus), also known as the common anaconda and water boa, is a non-venomous boa species found in South America. It is the heaviest and one of the longest known extant snake species. The term anaconda often refers to this species, though the term could also apply to other members of the genus Eunectes.