The Armenian Genocide began in April 1915, when the Ottoman government in Istanbul rounded up hundreds of Armenian intellectuals and deported them to Ankara. Soon afterward, an order was issued to relocate ethnic Armenians away from Turkish-inhabited areas through death marches. This relocation program was accelerated after the Siege of Van, during which Armenian defenders attempted to resist the invading Ottoman armies. Those who managed to survive the marches were sent to extermination camps located along the present-day borders of Iraq and Syria. Starting in 1919, the perpetrators who had not already fled Turkey were court-martialed, but the Pashas who were the heads of the Committee of Union and Progress (the political party that carried out the genocide) had already fled the country.
To this day, the Turkish government continues to deny that the Armenian Genocide ever took place, and resents the Armenian government for bringing it up regularly at international forums, making it a major bone of contention in diplomatic relations between the two countries. Referring to the Armenian Genocide as such remains illegal in Turkey.
Visiting the sites of the Armenian Genocide can be emotional, upsetting, and sometimes surreal. You'll see and learn things that are difficult to grapple with, and it's hard to anticipate exactly how you'll react. You may find yourself hurrying to get away from the site as quickly as you can, morose and weary as you physically feel the weight of what you're seeing, or unexpectedly detached and distant—or some combination of these.
Given the evil nature of the crimes committed in the Armenian Genocide, you would be forgiven for thinking the places where the crimes were perpetrated would look in some way evil too, or be in isolated locations tucked out of sight. This is not always the case, and the surroundings may often be positively mundane, and be in close proximity to roads, homes and workplaces filled with people going about their daily lives. The sun may be shining. It is this contrast between expectation and reality, or between horror and banality, that can cause you to feel strangely disoriented.
Be prepared for complicated and heavy emotions, and do not expect to just move on cheerfully to your next activity once you leave. Conversely, you may need to do just that. Your experience at the site may weigh on you for the rest of the day and beyond.