Convert from light year to legua [Spanish, pre-1568]

Unit Definition (light year)
The distance that light, moving at a constant speed of 300,000 km/s, travels in one year. One light year is about 10 trillion kilometers.

Unit Definition (legua [Spanish, pre-1568])
Unit of area used in the southwest US, equal to 25 labors, or 4428 acres (Texas), or 4439 acres (California). Also, a unit of length-- approximately three miles.