Dating to the early days of the city, Cobblestone in it's proper sense consists of roughly hewn stones varying from 3 to 8 inches long placed in an irregular arrangement in a soft base, usually sand.  The reason for the coarse surface was to maximize traction for both the horses hooves and the smooth wooden wheels that plied them in early days.  Later, the introduction of rubber tires (as well the the new lack of horse droppings cluttering the roads) put the tractive effort into the wheels themselves, thus leading to the desire for smoother surfaces, spelling the end for construction of new streets using the rough surface.

Most cobblestone has long since vanished from the city of Baltimore, though a few scattered examples persist in the area, with numerous gutters paved in cobblestone surviving.

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Today, what is more commonly referred to as "Cobblestones" is a misnomer.  This is in actuality Belgian Block, which consists of Granite Blocks cut to a regular size to be tightly fitted in a base bed of Concrete.  These blocks are usually laid perpendicular to the flow of traffic in an offest pattern similar to that on brick walls.  The blocks themselves typically consist of a variety of shades, from a deep grey to a light sand color.

Belgian block remains in many small stretches around the area, predominantly in the Fells Point area, where it anchored the paving of many streets lined with industrial railroad tracks.  Though offering a rumbly ride, the surface is particularly durable, and particularly aesthetic in historical areas.

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Another of the early paving materials used was one called Asphalt Block, consisting of long narrow asphalt blocks, primarily in two shades of a blueish gray.  This surface was apparently first used around the beginning of the 20th Century.  It appears that it was not particularly popular, judging by its rarity today.  In spite of this, asphalt would ultimately become the paving medium of choice for the majority of city streets, in its raw, sludgy, moldable form, for the creation of smoother thorofares.

The 20 foot length of Pleasant Street just East of Sharp street is about the only public street that retains asphalt block paving.  By and large, this medium has virtually vanished from the area.

Giving a hint as to what Asphalt block paving was like is this snippet of Falls Road just above the 28th Street Bridge, showing a portion of the medium hugging the rails of the old Ma & Pa Railroad.  This has since been paved over in 2003 in the creation of the Jones Falls biking trail.