Architectural drawings have long used geometrical tricks to convey scale, depth, distance and other three-dimensional aspects of realities on two-dimensional surfaces. In a two-vanishing-point drawing, the artist aligns their ruler with a point on one side or the other and draws a line along the edge (or employs another modular straight-edging tool).

The same came be accomplished much more quickly, however, using this simple technique: pin a flexible string to both points along the horizon line and slide a hook along the center. The results will naturally be a bit less than precisely linear, but for many architectural artists a wavy line is typical or even desired (it gives the piece a less rigorously complete look).

Of course, it will only work for a traditional two-point perspective – in cases where the artist wants to include a third vanishing point (for instance, to emphasize verticals in looking up at a skyscraper or create a fish-eye effect) a straight-edge is still required. That, or a free-handed approach based on a picture, presumably the basis of the drawing above.

A sports car parked in a residential alley, train emerging from a tunnel and helicopter landing next to the Colosseum are all believable sights in Italy’s capital … except in this case they are constructed from LEGO.

Italian photographer Domenico Franco imagines these block-built vehicles at human scale in his series LEGO Outside LEGOLAND, masterfully faked scenes of photo-realistic quality.

In his series, normal conveyances are swapped with LEGO creations that stand out as simplified block forms against the rich historical fabric of Rome.

While some are clearly toys writ large, others are more convincing: a passing glance at a tractor trailer doing road work might not immediately belie its fictional origins.

Landmark buildings and aged cobblestone roads come alive thanks to the contrast created by intervening toys. Ordinary gray-blue weather and aged architecture seems even more real than in a normal photograph.

“The aim is to transform ordinary contexts in extraordinary ones,” says the artist, “thus compelling the toys to get out of the idyllic and politically correct landscapes belonging to their perfect and idealistic cities, with the result of instilling in them those vices, virtues and desires typical of human beings.”

Calculated correctors, this team of vigilante street art fixers patrols for grammatical mistakes then regroups to decide on edits before hitting the streets of Quito, Ecuador, to deploy them.

Known as Acción Ortográfica Quito, the group consists of a trio who share a strange set of common interests including street art copy editing. Like rogue professors, they use red to highlight their changes or suggestions, but their good intentions do not render their actions legal, hence their strictly maintained anonymity.

“There’s a big difference in saying: ‘No quiero verte’ (I don’t want to see you) and ‘No, quiero verte’ (No, I want to see you),” notes one of the members in an interview with COLORS, “Many times, someone does not realize how a comma or an oversight can completely change the meaning of a sentence. It can change your life.”

The task can be daunting – their first fix had thirteen errors in two lines of text. Whether serious or silly, they suggest “it’s a public service and a moral obligation. We’re against spelling vandalism and we won’t break nor give up until we see a society free of spelling mistakes.”

Above, the phrase: “If in your kisses I met the essence of life, then not kissing you would be the worst sin I could commit,” for which these graffiti activists turned the verb into conditional, added and deleted commas, turned ellipsis into full stop and capital letter into lower case.

The group is also broadening its scope and mandate over time; they are aiming to add a hotline where people can phone in mistakes they spot and have begun correcting grammar on Twitter posts as well. When time permits, they also leave their name stenciled at the scene in red, like a grader signing their work for students.

Meanwhile, a similarly unconventional yet equally geeky German street artist is out to fix tags, turning them into tag clouds – it would seem this group is not alone in its quest to clean up yet preserve the essential meaning of everyday graffiti.

Presumed a prank at first by online skeptics, authorities have since confirmed that these precisely-stacked cinder blocks were indeed carefully assembled and bonded together to fully block the door of an S-Bahn train in Hamburg.

Placed inside the actual sliding doors, the bricks proved a surprise when the aperture slide open to reveal the blockage. Passengers who managed to board before the intervention was reported were forced to exit at an upcoming station while an investigation was performed and the problem ultimately fixed.

While some may be amused and no one was trapped inside the car, blocked by blocks, the impacts were significant for those faced with cleaning up after this vandalism. The train was routed to a depot and the wall carefully broken down piece by piece, the story ending 12 hours and an estimated 10,000 dollars later.

With no sign of the perpetrators, the biggest clue is the professionalism with which the wall was assembled, apparently by a team of people with construction expertise. With no one claiming credit, overtly or anonymously, one is left to wonder whether some reference to the Berlin Wall was intended or if this was an attempt at some other kind of art or message.

If you have spent any time along the High Line Park in Chelsea, you will recognize this extremely prominent billboard that one artist had the audacity to climb and hack away at.

The original message (WTF is alternate side of the street parking anyway?) was selectively deleted to make way for a replacement question.

Working at night, Poster Boy risked discovery by people parking and picking up their cars in the directly adjacent lot, not to mention being highly visible from the street.

During the day, visitors sitting in the over-street theater seats within the elevated park have a direct view of this huge black-on-yellow poster. It is doubtful the change will survive long, so check it out while it lasts!

Known for his creative edits of local signage and hacked infrastructure, Poster Boy has a huge collection of photos you can browse of his work, ranging from small stickers added in unusual contexts to whole-billboard transformations.