Hill Valley (Back to the Future)

Hill Valley is a fictional city from Back to the Future located in California. We get to see Hill Valley in 5 time periods:
 * 1855
 * 1955
 * 1985, normal
 * 1985, aleternate
 * 2015

Noteable Trivia

 * The drunk man who in 1985(normal) comments 'crazy drunk driver' after seeing Marty crash into the Town Building comments in 1985 (alternate) 'crazy drunk pedestrian' after Marty walks into his shopping cart.
 * The principal of Hill Valey Highschool has not had hair since at least 1955.
 * The Town Building is appears in all time periods except 1885.
 * The clock tower(or at least the face) appears in all time periods
 * In 1855, the clock tower has not been built, but the clock mechanism has been.
 * In 1955, the clock tower is struck by lightning and the clock badly damaged.
 * In 1985 (normal), the clock tower is in need of repair.
 * In 1985 (alternate), the clock tower has been converted into a high rise casino.
 * The Doc worried that Jennifer of 1985 coming into contact with Jennifer of 2015 would cause the end of the space-time continuum... it didn't.
 * Video games of 2015 no longer require the direct use of one's hands.
 * In 2015, the clock tower has been renovated into a mall with a large stained-glass entry way and underground features.
 * In 2015, Hill Valley is connected to its suburbs by flying cars that use the Skyway
 * In 1985 (alternate), Hill Valley High School is destroyed
 * In 1985 (normal), the mall has two names: it starts as Twin Pine Mall, but after Marty destroys one of the pine trees in 1955, he comes back to discover it has been renamed Lone Pine Mall.
 * Lightning from a storm in 1955 sets off a chain of events that spans from 1855 to 2015.
 * Marty crashes into the Town Building upon returning to 1985 (the first time)
 * Marty uses horses to draw his time machine up to 85 MPH in 1855
 * The citizens of 1955 Hill Valley had never seen/heard of skateboards, Darth Vader, reruns, Martin Luther King JR or Diet Pepsi.
 * The Twin Pine Mall has a JC Penny's
 * The hoverboard Marty uses in 2015 is a Barbie-style board by Mattel
 * In 2015, police officers wear hats with the phrase "Have a nice day" scrolling on an LED screen across the brim.
 * In 2015, trash cans move themselves around the city, automatically moving to where they are needed.
 * In 2015, floating street lights and traffic signs outline the Skyway
 * In 2015, a floating sign saying "Welcome to Hill Valley" has symbols representing the Rotary and Kiwanis clubs.
 * Sometime between 1985 and 2015 dust-resistant paper makes many forms of paper-preservation obsolete.
 * Only powerful or modified hoverboards work over water in 2015
 * After the courthouse is damaged in 2015, a flying, automated camera from USA Today flys in to take pictures.
 * The grassy commons from 1955 becomes an underground parking lot in 2015. The street running parrell to the clock tower on the other side of the commons becomes a 'No Landing Zone' in 2015.