My invitation to send questions about puzzling sights along freeways drew a strong response.

Curious commuters asked about lonely cemeteries, lighted monoliths and crooked reflectors. They wanted to know about the mountain rising along I-71 and the peninsula appearing suddenly near Rt. 315.

I received more questions than I could answer, at least in round one:

Q: I would like to know about a mound. It's on I-71 south, not too far past the sewer plant.

-- Christina Traven, Columbus

A: The Franklin County Landfill inspired several inquiries -- and no wonder: The man-made mountain of trash is one of the highest points around.

About 90 percent of the county's trash goes to the landfill, on Rt. 665 just west of I-71.

At 120 acres, it ranks as the fifth-largest public landfill in the country, according to Waste News, an industry publication.

The top of the landfill is 1,010 feet above sea level. The highest point in Franklin County, in the northeast corner near New Albany, is 1,132 feet.

The impressive mountain of trash will get bigger but not much higher, said Michael Long, director of the Solid Waste Authority of Central Ohio. It will top out at 1,020 feet and eventually cover 363 acres.

How soon is an open question.

"If everybody recycles, we can slow it down,'' Long said.

Q: What is that small cemetery next to I-70 on a small hill between Eureka Avenue and Harper Road?

-- Steve Vlasic, Columbus

A: What a forlorn spot.

Motorists traveling east on I-70 toward Downtown get a glimpse of an old cemetery next to a railroad track on the West Side -- just west of the W. Broad Street exit.

Some readers asked whether it's a Civil War burial ground. It's not.

The graves are contained in the Asylum Cemetery, where some residents of the Central Ohio Psychiatric Hospital -- once called the Central Ohio Lunatic Asylum -- were buried. The last wing of the hospital, an enormous edifice where the mentally ill were institutionalized, was demolished in 1991.

The cemetery, which consists of three adjacent burial grounds, includes the final resting places of some inmates -- such as executed murderers -- from the Ohio Penitentiary, said Lois Neff of the Hilltop Historical Society.

Leona Gustafson, who maintains a Web site (homepages.rootsweb. com/~rocky/Franklin_Cemeteries) on Franklin County cemeteries, has counted more than 300 graves in the portion of the cemetery visible from I-70.

Many of the headstones contain names and dates of birth and death. A few are marked "Unknown.''

The cemetery is maintained, but the graves are devoid of decoration. The rush of traffic on I-70 simply reinforces the feeling of a place for people who never found their way in the flow of society.

Q: Two steel posts with solar- panel devices affixed to the top of each are situated on I-70 in Madison County. For what purpose is the electricity generated?

-- James Larson, West Jefferson

A: The two posts between mile markers 80 and 81 on I-70 are solar- powered traffic counters.

A cable in the pavement measures the size and speed of vehicles, and sends the information to boxes next to the posts. The data is then transmitted by telephone lines to an Ohio Department of Transportation office, said Tony Manch, a traffic engineer.

Knowledge about the number and types of vehicles using I-70 helps in planning highway projects. It also gives conspiracy theorists something to mutter about.

Just west of the traffic sensors, at the Rt. 29 exit, is another slender device: a weather station, topped by a wind gauge. The station relays the pavement temperature, wind speed and other information to a maintenance site. The data helps the department know when to salt the interchange to prevent ice from forming, said Ned Kerstetter, interstate maintenance coordinator. An even higher-tech device is installed on the ice-prone ramp from westbound I-270 to Rt. 315. It uses radio waves to collect traffic and weather data.

Unlike the Rt. 29 weather station, Manch said, most of the equipment is buried in the pavement.

Q: Reflectors in the right lane of a stretch of I-270 (just west of I-71 near Grove City) must have been installed by a significantly impaired man or machine. The reflectors are installed in a manner that looks like a failed sobriety test.

-- Tish Hevel, Dublin

A: Despite their appearance, the off-kilter lane reflectors were installed by sober people, I'm told.

They are crooked on purpose.

The state is testing to see which reflector best withstands the impact of a snowplow blade, Kerstetter said. Installing them in wavy lines ensures that a snowplow blade hits them.

If the reflectors were aligned with the white lane markings, plow drivers would avoid them.

Q: Please find out about the man-made peninsula on the west side of Rt. 315 just north of the Wilson Bridge Road overpass.

-- John P. Wanous, Columbus

A: Several readers inquired about the "peninsula,'' which seemingly appeared out of nowhere at the northeast corner of Wilson Bridge and Olentangy River roads.

The dirt was excavated from the southwest corner, where Camelot Homes is building Maple Hill Retreat, a subdivision of houses costing $400,000 or more each. It was moved to the northeast corner at the request of the landowner, who wanted to fill in the ravine there, partly to deflect freeway noise, said Pat Bigler of Camelot.

The earth was graded and planted with grass, Bigler said, for erosion control.

The small red flags at the edge mark the erosion-control fence.

The landowner could not be reached for comment, but, said Bigler, the owner has no immediate plans to build anything there. And no building permit has been requested for the site, a Worthington official said.

Q: On eastbound I-70 approaching Downtown (across the freeway from Miranova), three stone monoliths are illuminated at night. What are they? What do they mean? Who did them and when?

-- Tom Linzell, Columbus

A: The monoliths, titled "Needles of Stone,'' were designed by landscape-architecture students at Ohio State University to decorate the Furnace Street electrical substation, a city facility built in 1989.

With the substation a prominent sight on the freeway, the city wanted to enhance it with artwork.

The monoliths, states a brochure from the substation dedication, are designed "to invite curiosity about the nature of the substation and about energy.''

They recall the ancient belief, demonstrated at places such as Stonehenge, that energy could be tapped through the careful placement of objects.

With fuel-consuming cars racing past a fuel-consuming substation, that stretch of freeway is, indeed, an energetic place.