Huntsville is pretty in the spring. It’s green and hilly, skirting the edge of the piney woods of east Texas. Yesterday I saw the first bluebonnets of the year, a burst of color alongside a city street. Wisps of redbud splayed across my path as I walked a wooded trail, and the smell of dogwood was enough at times to make me semi-drunk.

There’s history in the air, too. Sam Houston is buried here and although he died in 1863, his footprints are everywhere — from the university that bears his name, a grand monument in a storied old cemetery, a 15-acre museum and grounds to an enormous concrete statue on I-45 south of town. The general who won the battle of San Jacinto and served Texas as president, governor and U.S. Senator shares a birthday with the state he loved and led. Texas turned 180 years old yesterday. Big Sam would have been 223.

But there’s something else in the air here. It’s ominous and heavy and a little sickening. It hangs in the heart the way a meal you shouldn’t have eaten hangs in your gut, the foreboding of a price to pay, down the road.

Huntsville is the historic home of the Texas prison system. The place is ringed with sprawling prison campuses surrounded by tall fences topped by razor wire, guard towers at the corners. The names Goree, Ellis, Wynne, Holliday and Byrd are as familiar as city streets. Thousands of local citizens work in that system, and thousands of men are incarcerated behind those walls.

We’ve all seen prisons. They built one in my hometown back in the late 1980s. It’s hard to miss those fences, those towers, as you drive the roads of Texas. Most of them have the same look — clean and modern, well-kept and tightly secure.

But there’s one here that’s really spooky. It’s the Huntsville Unit itself, also known as “The Walls.” Just two blocks off the square, it has a three-foot-thick red brick wall from 15 to 20 feet high all around it — a huge, imposing structure right in the heart of the city. It’s the oldest prison in the system, once centered right here but now comprising more than 100 units scattered throughout the state. Those prisons, state jails and other facilities hold more than 148,000 inmates.

The Texas Department of Criminal Justice, with a budget of more than $3.3 billion, long ago outgrew its headquarters, just across the street from the Walls. That old administration building now houses mostly computers. There’s a convenience store next to it, with gas pumps and a sandwich shop on a busy commercial street. A sign nearby boasts that they will cash those TDC release checks for you.

There are 1,700 inmates at the Walls, mostly docile, middle-aged men who’ve spent the majority of their lives behind bars. Death Row is up north now, at the Ellis Unit, where 253 prisoners currently await execution. When the appeals are exhausted and it’s time for that final act, they bring them to Huntsville — inside the Walls.

The Walls has just eight death row cells, but normally there’s only one inmate there, driven to Huntsville on the morning of the day the sentence will be carried out. He (or she — the state currently has four women awaiting execution) spends the day there, and sometime after 6 p.m. he’s taken to the execution chamber, strapped to a gurney, and in an adjacent booth the executioner does his work. There are separate viewing rooms, and separate ways in and out for the inmate’s family and the victims’ family members who choose to view the execution and hear the murderer’s last words.

This reads like a travelogue, a collection of facts about a place where something happens that most of us would rather not think about. I admit, it was a morbid curiosity that drew me to that old prison. I drove the street around it several times, stopped and took a picture or two. But what struck me more than anything was the peaceful beauty of the place, a quiet residential street with houses, trees and flowers. It’s easy to imagine children playing there — and on the corner, that terrible and terrifying brick wall with the guard tower. The next day, on a visit to the Texas Prison Museum, I learned that the death chamber is in fact directly under that tower.

The museum recounts dramatic events, like the time Bonnie and Clyde busted one of their friends out of prison, or the notorious “Trojan Horse” standoff and escape attempt by Alfredo Carrasco in 1974. A display case memorializes corrections officers killed in the line of duty, and an exhibit contains quotes and portraits of family members of murder victims as well as the murderers, all mournful, all poignant, some biting in criticism of the system, some resigned, some satisfied that justice was done. What they had in common was loss, senseless acts of violence and the state’s quiet but inevitable retribution, played out behind the walls that loom over this beautiful town, even on a spring day amid the dogwoods and redbuds.

It’s a heavy, necessary business, but one most towns are happy to stay out of. Huntsville had no choice.