Entry No. 21 — the Indianapolis file — filed under: sensory art
Chatham Passage
A sensory, subterranean public art installation by Sean Derry where a sunken vault covered by a lace-like steel grate wafts the scent of fresh roses and projects shimmering LED lights into a historic alleyway.
The story
If you aren't paying attention, you'll walk right past the narrow squeeze between 745 and 747 Massachusetts Avenue without a second glance. It looks like a standard-issue urban gap—brick walls, asphalt, utility lines. But step into the alley and look down: embedded in the ground is an intricate, lace-patterned COR-TEN steel grate covering a sunken concrete vault beneath the pavement.
Installed in 2010 as part of the Indianapolis Cultural Trail, the piece is the work of artist Sean Derry (born in Homer, Alaska). Derry took the industrial grit of an urban utility vault and transformed it into a subterranean sensory trap. Below ground, he installed an automated scent machine alongside an array of LED lights. Instead of sewer gas or stale alley air, the grate continuously vents the distinct, unmistakable scent of fresh roses directly up into the walkway.
It's public art designed as a glitch in your urban routine. Hundreds of people stride across Mass Ave every hour oblivious to what's under their shoes, but if you know where to pause, the subterranean light show and sudden floral blast turn an everyday alley shortcut into a quiet mind-bend.
What it's like
Navigate into the alley between 745 and 747 Mass Ave and look for the rusted, ornate steel grate set into the ground. Stand directly over it to catch the subtle glow of LEDs illuminated inside the concrete pit below. The rose scent wafts up in gentle bursts—sometimes faint, sometimes surprisingly potent depending on the breeze and timing. Visit after dark for the best experience, as the subterranean lights cut through the shadows beneath your feet without the daytime glare.
The move: Take an evening stroll down the Mass Ave alleyway, stand directly over the grate to catch the unexpected floral scent, and watch the subtle light show escape from beneath your feet.
- 📍 Mass Ave Arts District
- 💸 $$
- ⚡ Up for anything
- 🌗 Indoors
Where: Alleyway between 745 and 747 Massachusetts Ave, Indianapolis, IN 46202
Hours: Added 2026-07-21 — confirm current hours before you go.
Pair it with
- Wiseguy Lounge — Pair a subterranean floral alleyway surprise with a hidden, dim-lit bourbon lounge tucked behind the back door of a nearby pizza joint.
- The Aroma Labs at Bottleworks — Double down on sensory scent experiences by heading three blocks up Mass Ave to blend your own custom fragrance.
- Bootleggers — Keep the subterranean theme going by heading south to ring the bell for entry into a gritty prohibition basement bar.
- The Harrison Center — Head under a mile north to trade hidden outdoor sidewalk art for 36 active artist studios inside a historic 1903 Gothic Revival church.
Good to know
Where exactly is Chatham Passage?
It's built into the ground of the alleyway situated between 745 and 747 Massachusetts Avenue in the Mass Ave Arts District.
Who created the installation?
It was designed by artist Sean Derry and commissioned for the Indianapolis Cultural Trail.
Does it cost anything or have opening hours?
No, it is a free public art piece set into an open alleyway and accessible 24/7.
How does the installation actually work?
A underground cement vault beneath a custom COR-TEN steel grate houses a scent dispenser that pumps out rose fragrance, paired with internal LED lights that project upward.
Plan a visit & invite your people →
Further reading: Atlas Obscura · indyculturaltrail.org
last checked: 2026-07-21