The park and its immediate surroundings contain a number of historic structures, some of which date to the pre-Civil War period.
Most of these structures are railroad remnants, including intact stations at Vienna, Sunset Hills, Herndon, Hamilton and Purcellville,  stone arches and culverts, the piers and abutments of bridges, and a relocated passenger shelter (formerly at the site of the Clarks Gap station at the present crossing of the trail and Dry Mill Road (VA 699); now at the former site of the Paeonian Springs station near Simpson Circle).

Part of the reinforced concrete floor of a brick electrical substation that the railroad constructed in 1912 to help supply power to its new electric locomotives and trolley cars is visible in Arlington County's Bluemont Junction Railroad Display south of Wilson Boulevard.
The floor is located in the space between a soccer field and a Southern Railway caboose.

A remnant of a coal trestle stands south of the W&OD Trail, west of the trail's crossing of Lee Highway (U.S. 29) in Arlington.
 In June 2014, the owner of a property adjacent to the regional park demolished part of the structure to provide space for a planned self-storage facility.
At the time, the Arlington County government was considering a proposal to designate the structure as a local historic district.
In September 2014, the Arlington County Board designated the remaining portion of trestle, which was located on NVRPA property, as a local historic district.
 The trestle was once adjacent to the west side of the railroad's Falls Church (East Falls Church) station, which was dismantled after the railroad closed.

A white metallic marker post lettered in black with the words "Station 1 Mile" stands on the north side of the trail west of Little Falls Road near the boundary between Arlington and Falls Church.
This post, which once stood next to the W&OD Railroad's tracks, is one mile (1.6 km) east of the site of the railroad's demolished West Falls Church Station.
The station was located near the east side of the railroad's crossing of W. Broad Street (VA 7) in Falls Church.

Near the east end of Vienna, the poured concrete abutment of a bridge that carried an interurban trolley line, the Washington-Virginia Railway, over the W&OD Railroad remains on the north side of the trail.
 An inscription showing the month and year of the abutment's construction (July 1904) is visible on the structure's east side.

The trail crosses Goose Creek in Loudoun County on a span that NVRPA built on top of the piers and abutments of the highest and longest (268 feet (82 m)) bridge that the railroad constructed within the present boundaries of the regional park.
 Visitors can view these remnants and the intact span, pier and abutments of the railroad's deck girder bridge over Sycolin Creek from unpaved paths that travel between the streams in NVRPA's Two Creeks Trail Area on the north side of the trail.

The Sycolin Creek bridge bears the only remaining span that once carried trains of the W&OD Railroad.
As the trail travels on the concrete deck of the bridge, visitors can only see the span and the structures below if they leave the trail.

The piers and abutments of the railroad's bridge over Tuscarora Creek are visible south of the trail near the east end of Leesburg.
 The bridge was the second longest (149 feet (45 m)) that the railroad built within the present boundaries of the regional park.
 The piers and abutments are the only ones along the trail's route that do not presently support a bridge.

Remnants of the facilities of a 19th-century lime company are visible in Leesburg on the northeast side of the trail, southeast of Harrison Street SE.
Limestone (calcium carbonate) from a company quarry was mixed with coal and burned in a nearby kiln that was adjacent to the railroad's tracks.
Quicklime (calcium oxide) was brought out of the kiln through two arched openings that visitors can see from the trail.
The company also supplied farmers with agricultural lime and provided builders with lime plaster for walls and stone for roads.

Near the sad
The park and its immediate surroundings contain a number of historic structures, some of which date to the pre-Civil War period. Most of these structures are railroad remnants, including intact stations at Vienna, Sunset Hills, Herndon, Hamilton and Purcellville,  stone arches and culverts, the piers and abutments of bridges, and a relocated passenger shelter (formerly at the site of the Clarks Gap station at the present crossing of the trail and Dry Mill Road (VA 699); now at the former site of the Paeonian Springs station near Simpson Circle).
Part of the reinforced concrete floor of a brick electrical substation that the railroad constructed in 1912 to help supply power to its new electric locomotives and trolley cars is visible in Arlington County's Bluemont Junction Railroad Display south of Wilson Boulevard. The floor is located in the space between a soccer field and a Southern Railway caboose.
A remnant of a coal trestle stands south of the W&OD Trail, west of the trail's crossing of Lee Highway (U.S. 29) in Arlington.  In June 2014, the owner of a property adjacent to the regional park demolished part of the structure to provide space for a planned self-storage facility. At the time, the Arlington County government was considering a proposal to designate the structure as a local historic district. In September 2014, the Arlington County Board designated the remaining portion of trestle, which was located on NVRPA property, as a local historic district.  The trestle was once adjacent to the west side of the railroad's Falls Church (East Falls Church) station, which was dismantled after the railroad closed.
A white metallic marker post lettered in black with the words "Station 1 Mile" stands on the north side of the trail west of Little Falls Road near the boundary between Arlington and Falls Church. This post, which once stood next to the W&OD Railroad's tracks, is one mile (1.6 km) east of the site of the railroad's demolished West Falls Church Station. The station was located near the east side of the railroad's crossing of W. Broad Street (VA 7) in Falls Church.
Near the east end of Vienna, the poured concrete abutment of a bridge that carried an interurban trolley line, the Washington-Virginia Railway, over the W&OD Railroad remains on the north side of the trail.  An inscription showing the month and year of the abutment's construction (July 1904) is visible on the structure's east side.
The trail crosses Goose Creek in Loudoun County on a span that NVRPA built on top of the piers and abutments of the highest and longest (268 feet (82 m)) bridge that the railroad constructed within the present boundaries of the regional park.  Visitors can view these remnants and the intact span, pier and abutments of the railroad's deck girder bridge over Sycolin Creek from unpaved paths that travel between the streams in NVRPA's Two Creeks Trail Area on the north side of the trail.
The Sycolin Creek bridge bears the only remaining span that once carried trains of the W&OD Railroad. As the trail travels on the concrete deck of the bridge, visitors can only see the span and the structures below if they leave the trail.
The piers and abutments of the railroad's bridge over Tuscarora Creek are visible south of the trail near the east end of Leesburg.  The bridge was the second longest (149 feet (45 m)) that the railroad built within the present boundaries of the regional park.  The piers and abutments are the only ones along the trail's route that do not presently support a bridge.
Remnants of the facilities of a 19th-century lime company are visible in Leesburg on the northeast side of the trail, southeast of Harrison Street SE. Limestone (calcium carbonate) from a company quarry was mixed with coal and burned in a nearby kiln that was adjacent to the railroad's tracks. Quicklime (calcium oxide) was brought out of the kiln through two arched openings that visitors can see from the trail. The company also supplied farmers with agricultural lime and provided builders with lime plaster for walls and stone for roads.
Near the sad
Washington & Old Dominion Railroad Regional Park